Archive of Our Own ^beta

Chapter Text

The prisoner was silent as they dragged him off the transport.

Prowl frowned, squinting as he focused on the figure through the harsh reflective glare of the dry, corrosive landscape.

Before he could get a proper threat assessment, the winds picked up from the east. The troop transport yawed to the side, its landing clamps hissing under the strain. An empty storage crate slid across the ground, flipping end over end, sending support troops scrambling.

“Get that shield back up!” Prowl shouted over the clamor, grit getting between his teeth, an instant crunchy sensory nightmare. He stepped back beside a pillar to block the worst of it pelting at his face and joints.

The crate took out a mech at the knees. Static charge built, clinging to everything — wires, vents, plating — carried on the magnetic fluctuations in the wind, picking up whatever was not nailed down.

“Shield, now!” The magnetic charge made Prowl’s cortex ache. His HUD split in multi-coloured shimmers as he tried to abort his battle computer’s frantic calculations of every loose object strewn around the landing platform, and their reclassification into ‘potential deadly projectile.’

A magneto-static rust-cloud swirled into a funnel, sucking up debris over a recycling bin at the same time Prowl’s HUD spat to lines of distortion.

The lights beneath the catwalk flickered, creaking as they swayed. The shield generators hummed in an oscillating tone, over-clocked as more power diverted to them. The pitch was off. The pattern wrong. There were too many variables to track.

The humming grew louder, blotting out the command queue of Prowl’s battle computer.

His HUD flashed to white.

Crashed.

He stood frozen. Doorwings stiff. Joints locked during reboot. Unable to access motor controls. Paralyzed. Unable to give commands. Mute. Unable to do more than listen. Blind.

Countless clatters echoed across the landing field as everything airborne dropped. The wind lost its fury, and the static its snapping bite. The electroshield-dome must have closed. The generators stabilized, and so did Prowl.

He pinched the bridge of his nose, wincing, riding out the stabbing pain behind his optic as his battle computer came back online. Able to aggregate information from all his sensors and perceptions beyond the awareness and capabilities of other mechs, the instant it was back online — he knew the dying breeze flowing past his neck was wrong.

It was a subtle change in the airflow. He could sense it. An object that hadn’t been there before his crash.

His optics snapped open. Hand frozen at his face. Every alert in his frame already screaming at him not to twitch. 

Don’t. Move.

At first, all he could see beyond the pillar was light and shadow passing through varying densities of billowing sand — his targeting systems locked on the sand’s movement — twisting and spiraling in lazy, settling plumes. 

But there, where the air moved wrong, diverted course — was a large, sharp piece of scrap hovering microns from his neck. It wasn’t embedded in the pillar; it wasn’t hovering mid-air.

It was being held.

Held steady, bypassing his armored shoulders and collar faring, at his main energon line.

The pounding of his fuel pump echoed in his audials, drowning out all other noise.

The rusted-dust cloud thinned. A rolling thunder rumbled in the distance as a broad, shadowed figure emerged. Optics burning like fire, the silhouette blurred in heat-shimmers and rust-laced contrails, as if struggling to hold its shape without a strong wind to carve its edges into focus. Wisps of electro-static charge trailed from its thick-blunted antenna-based horns — off into the swirling eddies curling about its heavy armor.

Ruststalker, Prowl’s battle computer unhelpfully supplied as his throat ran dry of oral lubricant.

Before his own rationality fought against it: asserting that the probability of a ruststalker existing was exceedingly low.

The veil of dust thinned further, settling — and myth hardened into mech. 

A deep rust-red coated mech, taller than Prowl, his armor finish abraded to matte where its sheen had been sanded away by magnetized-rust winds. His helm was black, audial horns chipped to bare silver along their ridges.

The prisoner — not legend, not myth —held a sharp-edged, rusted-out chunk of scrap to Prowl’s throat. 

Prowl’s throat tightened as he traced the white on this mech’s thighs — or what used to be white. Stained orange, rust-washed, as if he’d been wading for months in iron rot. And what was that? A little stamped imprint on his black pelvic guard: a line above a triangle pointing down — 

He tore his glance away before his curiosity betrayed him, locking a commanding glare onto optics so caked in rusted sand along their rims it was a miracle the mech could even see.

But the mech had caught Prowl’s quick assessment — notably, his a-little-too-long wandering gaze up the mech’s thighs, resting at their apex.

The hard-set faded from the prisoner’s expression. A knowing smile tugged across the dusty terrain of his face, taking its place. 

“You should strap things down and invest in some screw top lids,” the prisoner said, as Prowl calculated the trigonometric trajectory to the origin point of that exact piece of scrap. 

His doorwings twitched as his calculations completed.

The prisoner had intercepted the scrap from its lethal path while Prowl was bricked during reboot. Soldiers in the landing area were only now finally beginning to realize they had lost their prisoner. The mech himself held the scrap at Prowl’s throat a fraction of a moment longer, then lowered it. He flipped the asymmetrical, unbalanced weight of it with an uncanny, fluid ease, then extended it to Prowl. 

“Scrap can be lethal around here.” He winked.

Winked.

Unkempt, stained, and chipped though he was, his blinding smile flashed a row of perfectly kept teeth with two glinting sharp fangs — an unsettling contrast to the relaxed shift of his weight on his hips. Casual, but loose and ready to roll with whatever Prowl threw at him. Yet he remained half-focused, like someone not entirely all there behind his rim-crusted optics.

Someone who was only putting in a bare minimum of effort talking to him.

Instantly annoyed this mech didn’t process Prowl as either authority or a threat, his doorwings flared. A hot, frustrated vent forced from his nose and he snatched the scrap from the prisoner’s hand with far more force than necessary.

“Who uncuffed him?” He snapped at the soldiers, whose reactions were always so painfully slow compared to the information Prowl could process in a fraction of their time.

“Apologies, Commander,” one of them jogged forward through the settling dust, and reattached cuffs back around the mech’s wrists. He tensed for resistance, but none came. “The magnetic charge in the static funnel must have shorted them.”

“Must have.” The prisoner shrugged, the growing smirk on his face stoking Prowl’s irritation further.

“Take him to the processing cell. Weapons on him.” Prowl gestured with the heavy chunk of scrap at the returning unit. “Smokescreen with me.”

The prisoner allowed Prowl’s soldiers to push him forward with their weapons, but he didn’t stumble. Didn’t falter. 

 Prowl kept watching until the mech was escorted out of sight, his battle computer spitting error after error. That mech didn’t walk like a soldier or a nervous civilian. His gait was uneven, yet strangely rhythmic, the rusted ground barely shifting beneath each step, as if the heavy armor he wore weighed nothing to him at all.

“What do we know about him?” Prowl asked his second in command as Smokescreen came up beside him.

“Carrion scavenger, looks like,” Smokescreen replied. “Patrol found him picking through the wreckage of a seeker squadron. East flank, three leagues deep into the boundary line.”

Prowl’s severe expression didn’t change, but the furrow between his optics deepened as he reviewed his reports, coming up empty. “No one reported we took down a squadron.”

“We didn’t,” Smokescreen said. “Storm must’ve got them.” He jerked his head toward the transport. “We grabbed a few of their heads. Datarider checked their flight logs on the way back. Magnetic bursts scrambled it, but from the bit we could download, the flight patterns suggest a full-scale panic scatter.”

“No survivors?”

“None that we found, but one of the Hexagon’s hurricanes was stalking across on the horizon, making everyone twitchy.” Smokescreen gestured around at the debris strewn across the landing platform. “With how quickly storms build from nothing around here, can’t really blame them.”

“And today’s forecast was a good day,” Prowl muttered, glancing from the piece of heavy scrap he held, and off into the distance. 

A good day was still stiflingly hot, the horizon rippling with heat haze over the high desert that stretched as far as the optic could see.

Tornadoes stalked the dune sea in slow procession, static-laced funnels taller than Iacon’s tallest spire twisting across the rusted surface. They split, merged, and circled one another. Some brushing by each other with barely a touch. Others combined forces to swallow smaller rivals. 

From his balcony, looking out over it all, Prowl sometimes swore he saw them fight, then separate. 

Calm today, by Rust Sea standards. Funny when that meant only a few destructive funnels roaming today, with the dark, spreading stain of one of the Hexagon’s hurricanes brooding on the horizon.

The Rust Sea was a grave — a seemingly endless, wind-blasted expanse of oxidized sand, and flaking scrap dunes. Located at Cybertron’s northern magnetic pole, it was encircled by the Manganese Mountains, the Acid Wastes, and the flying mountainous region of Vos shadowing the rest.

Up here, sheltered in foothills of the Manganese Mountains, the tornados lost whatever advantage the sea gave them for their size. The biggest storm, the Hexagon, an ever-storm that was bounded by six hurricanes which sculpted its strange boundary layer shape from orbit.

Nothing flew over the Hexagon; anything that flew over it lost power. Its magnetic fields stripped the skies bare, spitting wreckage into orbit before dragging it back down.

Every report Prowl had studied about the topography defining the Rust Sea, in preparation for his command of the outposts here, agreed: the Hexagon never left its sea of strewn decay. There was no record of it ever crossing the boundary line.

Nothing lived beyond the boundary line.

Not for long.

Nothing sane, anyway.

The exiting commander had warned Prowl that no one crossed beyond sight of the shore into the Rust Sea and came back the same. The magnetic distortions messed with mechs’ memories. Corrupted systems. 

A miracle, if anyone came back at all.

And yet, the seekers of Vos had been trying — more often of late — to circumnavigate the pole. It was clear to Prowl they were hoping to catch the Autobots unawares along this less defended flank that cut over Praxus, en route to Iacon.

Politically, the city-state of Vos still feigned neutrality, but they had allied with the Decepticons. Which left Praxus alone. The final hold out. The last neutral city on all of Cybertron.

The last hope this war could still end without mass casualties.

And Prowl would be damned if he let that hope fall.

Prowl’s jaw twitched as his battle computer forward projected probabilities. He didn’t like this new development of a mech found skulking about within the sea.

Not one bit.

“Does he have an ID?” Prowl asked, while already knowing the odds.

“Nothing in our records,” Smokescreen’s tone was almost casual, though his mouth twitched toward a frown. “No faction marks. No Decepticon insignia. Not even a production stamp.”

Prowl looked up sharply. “A blank?”

Maybe that’s what was itching in Prowl’s battle computer about him — what was wrong with him.

A blank was rare. Energy intensive and time consuming to raise from a spark-born protoform to full adult frame. Inefficient. Aimless. Difficult to focus into becoming a productive member of society. 

Better to be constructed at full efficiency and power.

Smokescreen shrugged one shoulder. “Could be off-grid. Could be old. Could be built for a purpose outside of official production. There’s no traceable origin in his spark code. If he ever had a vehicle identification number or a civic ID, it’s been scraped out.”

Prowl’s battle computer kept churning with options. “A Decepticon deserter? Assassin? Or insane?”

“Any of them’s possible,” Smokescreen said. “Except… he didn’t even know about the war.”

Prowl’s head snapped toward him. “What?”

“Didn’t recognize our insignia.” Smokescreen shook his head like he didn’t quite believe it himself. “Didn’t recognize the word ‘Autobot.’ Asked if ‘Decepticon’ was some kind of new religion.”

Prowl stared, battle computer empty of permutations. He blinked once. 

Taking a step forward, Smokescreen leaned in, nervous the troops setting the landing platform back to right would hear. 

“He says he lives in the Rust Sea.”

“What part?” Prowl asked, slowly shifting the sharp chunk of scrap in his hand.

“All of it.”

Chapter Text

The interrogation room was small, walls pressing close with little space to move around the furniture. Prowl’s own design, but he hadn’t had much to work with.

Big enough for a simple table and two chairs — though Prowl always stood. A retrofitted storage space, divided into observation and two brig cells. To date, he had only ever used them to sober soldiers, or cool heated tempers.

Under Prowl’s command, make-shift brigs like these had been added into every Autobot outpost through the Manganese Mountains. All of them had been set up to his precise specifications.

Neutral grey-orange. Matte. No reflective surfaces. No tactile distractions.

Or so Prowl thought.

For twenty minutes, Prowl had watched the unknown mech stand on the table and vocalize into the ventilation fan, entertained by the way the blades chopped sound into a warble.

Seeing no sign of the mech’s nonsense ending any time soon, Prowl shared a pointed glance with Smokescreen, then leaned over the intercom.

“We will not enter until you sit,” Prowl said, his commanding tone direct and to the point.

The mech had the presence of mind to follow directions at least, but only in a technical sense.

He sat.

On the table.

“On the chair behind you, if you please,” Prowl said, scowling at Smokescreen as his batch-mate snickered the moment Prowl lifted his finger from the intercom’s button.

Their prisoner cocked his head to the side, glancing up at the camera for the first time. Prowl predicted he was going to argue, but he rolled backward off the edge of the table, defying his bulky anatomy, and landing deftly on his pedes.

Then, as if submitting to gravity was a chore, slumped into the chair and blew a wave of air from his vents in a huff.

Curious, Prowl waited for an outburst, a question, a reaction — anything that would give Prowl a little more insight into the temperament and stability of this mech.

But he simply sat there, suddenly still.

Unnervingly still.

He didn’t fidget, didn’t shift.

Didn’t even blink to recalibrate his optical sensors.

It was as if his frame was on standby and his consciousness was suddenly somewhere… else.

Even when Prowl and Smokescreen entered the room, he still didn’t move. Didn’t look at either of them. No shift in his frame or optics that indicated a ruse, or hostility.

He just sat there. Distant.

He was either very good, or the Rust Sea had scrambled him to the far side of sanity.

Prowl hoped to learn he was dealing with the former, rather than the latter.

“Designation?” Prowl asked as Smokescreen sat across from the prisoner, datapad in hand, ready to look busy filling out the first space on the intake form.

The mech’s gaze lifted and Prowl’s vents caught. His optics weren’t completely red beneath the smear of rust-dust A vibrant blue-green bloomed at the centre, bleeding softly into peridot that melted into a rich rusted-reddish brown at the edges.

“Sideswipe.”

Prowl had to replay his memory file to catch the name; his focus had snagged on the mech’s startling optic colour.

A glint of patina copper ore, exposed by the waves of the dunes after a passing storm…

A shade Prowl’d never seen in any personnel or criminal file.

It seemed impossible that copper’s full spectrum of oxidized aging could be captured so perfectly in the gradient hues of a mech’s optics. Perhaps the variation had simply been scored across the surface from the rust storms —

Or polished smooth on the shores of the glass beach —

“Assigned name, or civilian?” Smokescreen took over the questioning as Prowl blinked, trying to recalibrate his colour sensors, uncomfortable with the way his thoughts kept wandering. Especially once he realized his fans had stopped completely, and he had to subtly spin them back up, hoping no one noticed.

The rust-scored mech tilted his helm, still maintaining that unblinking, mechanimal-like stare.

He noticed.

“It’s what I’m called,” he said.

“Who assigned the designation to you?” Prowl asked, internally proud his vocalizer didn’t so much as crack.

The mech paused, considering, then gave a small shrug. “It’s what I’m called.”

“Who calls you that?” Prowl pressed.

“Sunny, mostly.” His optics went distant; his voice split into overlapping tones. “He curses my name the loudest lately.”

Slag. Did that mean there were more of them? Or, with a name like that, did this ‘Sunny’ exist outside his head at all?

“Where is Sunny?” Prowl prompted further, ignoring the high probability his prisoner was about to respond that Sunny was standing right next to them.

“Home,” came the distant response.

“Where’s home?”

The mech’s optics brightened slightly. “Rusty.”

Prowl blinked again. Sideswipe still hadn’t. “Rusty is… ?”

“My home.” His patina-hued optics sharpened on Prowl. “My city, in the Rust Sea.”

“The Rust Sea’s a wasteland,” Smokescreen said gently, as if to a soldier lost in a memory error. “There aren’t any settlements that can withstand the storms, let alone anything that could be considered a city.”

“I dare you to walk out there and say that when the wind is high,” Sideswipe’s unblinking focus snapped from Prowl, locking in on Smokescreen, scowling as if Smokescreen was the one with the memory corruption. “See for yourself. You’ll know the truth before you’re stripped to sand.”

As Sideswipe spoke, the blue-green light at the centre of his optics tightened to a ring, leaving only hues of orange and reddish-brown.

“Go on,” Sideswipe continued, tilting his helm the other way. “I can always use more sand to play with.”

The all encompassing intensity that was suddenly locked onto Smokescreen sent the threat assessment reading of Prowl’s battle computer sky rocketing.

It was as if a storm had blown in beneath Sideswipe’s optics, compressing the calmer blue-green into the centre of a hurricane, while rusted-iron ferocity built around it.

“You claim you live there?” Prowl asked, hoping to redirect the suddenly volatile prisoner back toward him. “In this city within the Rust Sea.”

“Yes,” Sideswipe hissed the word through his exposed fangs, still fixated on Smokescreen as if considering blasting him to sand himself.

But there was no sound of any weapons charging. So Prowl leaned forward and tapped the table. The rhythm drew Sideswipe’s unblinking stare away.

“If I brought you a map, could you point at the sector where we could find your city?”

“To what end?” His gaze slowly lifted from Prowl’s finger, the blue-green hues at the centre expanding back out as he raked his gaze up the length of Prowl’s frame. Like a wind caressing over a mountain spine, Sideswipe’s focus lingered on Prowl’s abdominal seams, tracing beneath the curve of his bumper, then lazily curling up the contours of his chest. “You looking to open relations between us, Commander?”

Prowl’s spark thudded once out of rhythm, knocked sideways. As his doorwings twitched, so too did the corner of Sideswipe’s mouth. Encouraged.

“You think I don’t already feel you,” Sideswipe continued, leaning forward on his elbows, resting his cuffed hands under his chin. “Teasing my edges. Lapping at my shores.”

He pushed forward on his forearms, arching the upper part of his heavy armor over the table, his words carrying a rhythm of fragmented melody that gusted through the air, caressing across Prowl’s face.

“But can you handle my heat?”

The fan above them abruptly spun to a halt — then started up in the other direction, forcing the hot, stifling outside air in.

A shimmer blurred the edges of Sideswipe for a second. He grinned, licking his lower lip.

The heat surged around them — into them. The more delicate internal circuitry of Prowl’s sensors warped. His HUD flickered erratically. The clear lines of his battle computer’s logic seeped in a bleeding pool, code creeping beyond its boundaries. His systems registered the magnetic shift, but not as an external threat.

It was as if the very data Prowl’s battle computer displayed was bending, the rational world momentarily contorting to fit an unsettling geometry that spiraled out into infinity.

As Prowl’s cooling fans faltered, struggling to compensate for the sudden charge in the air, Sideswipe kept staring at him.

Unblinking.

Like Prowl was the most fascinating mech that’d ever brushed up against his shores.

When they finally left the room, escaping the stifling heat, Prowl was already compulsively running simulations of the impossible.

Weather patterns and their sudden hurricane force winds, magnetized winds whipping up static-laced tornados, pockets of magnetic anomalies, lightning splitting nitrogen and oxygen and raining down nitric oxide and static charge building, warning of a strike. Of ever-shifting dunes and terrain maps that changed from one hour to the next that would cover any subterranean entrance or vents. Or entire structures. The rapid shifts from dry desert to stifling humidity that stressed any metallic material, and the sand-blaster effect that could erode a mech’s unshielded plating off in a matter of hours.

Every conclusion led to permanent settlement within the Rust Sea as impossible.

“I don’t think he’s bluffing,” Smokescreen said, watching the prisoner through the monitor.

“Delusional systems can fabricate realities,” Prowl replied, fixed on Sideswipe leaning back in his chair and resting his pedes on the table.

“Well, I don’t think he’s an infiltrator,” Smokescreen said. “You ever meet a ‘Con who fakes not knowing why we’re at war? One who looks confused when you say ‘Megatron,’ and asks ‘You mean Megatronus? Didn’t he die?’”

That turn in the interrogation had unsettled even Prowl.

Sideswipe spoke of Megatronus and the Thirteen Primes as if they’d been annoying neighbours he’d had to tolerate for a time — irritating while they lasted, then gone, assumed dead. He had even asked if Prowl was certain Megatronus hadn’t been resurrected and, when asked why he’d think that, cryptically responded: Primes are annoying like that. Difficult to kill. Even more difficult to keep dead.

Prowl didn’t answer Smokescreen. He was still watching the prisoner through the monitor feed. The infuriating mech stretched with an annoying grace, flaring his chest armor and drawing a slow ripple through his abdominal seams, cuffed hands resting atop his helm like a crown —

He was basking in there, brazen in the heat.

Hundreds of thousands of years had passed since the deaths of Megatronus Prime and the Thirteen — long before Megatron was inspired to take that name for his warframe.

There was no possible way Sideswipe could be that old.

But there was a strange timelessness to him… swimming beneath the patina hues of his optics.

The non-sense Prowl’s battle computer was being forced to keep analyzing, trying to get an assessment on Sideswipe’s true threat level was giving him a headache. Prowl had only looked away for a moment, rubbing beneath his chevron — when he heard a clatter.

He jolted, already dreading what he was seeing: the cuffs had dropped from Sideswipe’s wrists, and were sitting on the floor.

Hands clenching into fists, Prowl leaned over the monitor. “Split screen, replay that. Half speed.”

Half speed wasn’t enough. Neither was a quarter speed. Or an eighth.

No fractional speed revealed anything but the improbable. Sideswipe had simply been sitting there humming to himself when the cuffs, by all appearances, just failed and fell to the floor. Now he just sat there, stretched out and unconcerned, as if no consequence had touched him in his entire life.

Infuriating.

“He could have a disruptor on him somewhere we missed,” Smokescreen said. “The team was probably too nervous around him to search him properly. On the transport back, I was already hearing a few whispering he could be a ruststalker.”

Prowl stiffened, unwilling to give the superstitious speculation any weight. Yet, his battle computer’s threat models improved when he allowed for it — reminding him, unhelpfully, of the thought he himself had had when Sideswipe first materialized out of the storm.

“Superstitious hallucinations from mechs who’ve been in the heat too long with their coolant running dry,” he said. “The odds of us capturing a mythological monster —” he cut himself off.

The odds were higher than there being a permanent settlement in the Rust Sea.

Smokescreen took Prowl’s distraction as derision.

“Just saying what I heard,” Smokescreen said, folding his arms. “It’s that, or he’s walked ten thousand leagues through corrosion storms. Recycling his own coolant until it becomes sludge.”

“I don’t believe in myths,” Prowl said, mostly to reaffirm reality to his battle computer. Maybe it was broken — going rogue, about to drive him insane like everyone else in his batch program. He linked his hands behind his back as he fixated on the highest probability in the output. “It is more likely he crossed the boundary into the sea from the same direction as you. He can’t have been out there that long, or he’d be sand-blasted to scrap, and he’s clearly not.”

“You think he slipped through our lines from behind?”

“It’s the most likely probability,” Prowl said. “A small, reclusive group of inbred blanks who’ve been clinging to the mountains long before the Autobots built the outpost network. It’s not like the Rust Sea was an area of interest for resource extraction or vacation destinations before Megatron’s first slaughters.”

“Inbred?” Smokescreen wrinkled his nose. “You think that’s why he…” he trailed off, waving his hand absently. “You know, when he looks at me. Like he’s stripping me down to recycle my fluids and harvest my parts. But when he looks at you —”

“Watch it,” Prowl warned. “We may be batch-mates —” and thankfully Smokescreen had failed his entry into the Tac-Net Program or Prowl would be the only one left standing, “— but I am now your commanding officer.”

“So I was just imagining the way he was primed to pounce on you and download new code into himself? And you… ” Smokescreen suggestively waggled his doorwings in a mocking, fluttering slant.

“A mirage,” Prowl said, calculatingly monotone. “Due to the heat.”

“Regardless,” Smokescreen made the wise decision to drop it, “there’s something disturbingly off about him. This sense that even if I met him all cleaned up and polished, I’d hate to gamble against him.”

“I don’t like mysteries,” Prowl grumbled, irritated that Smokescreen had planted the image of Sideswipe cleaned up in his mind.

And worse, Prowl didn’t hate it.

Smokescreen gave a small snort. “You love mysteries.”

Behind his back, Prowl’s hands stretched then clenched again. “I don’t enjoy them walking out of inhospitable terrain shortly after I began my first command.”

“Technically… we airlifted him out, he didn’t walk.”

“Let you airlift him out, you mean.”

Smokescreen’s doorwings hiked up. “You think he killed all those seekers?”

“An entire squadron?” Prowl scoffed. “Unlikely.”

“You’re about to ruin my recharge, aren’t you?” Smokescreen groaned. “Fine. Just do it. What’s going to be making me keep one optic open as the storms batter and howl against our shield?”

“We don’t know exactly how dangerous this ‘Sunny’ is, do we?” Prowl frowned as he watched Sideswipe tilt the chair over on one leg to pick the cuffs up off the floor. He closed them and began spinning one end around on his finger. “I don’t like the probability that there’s another out there like him.”

As Prowl said it, Sideswipe looked straight into the camera —

And smiled.

A hurricane’s grin.

Chapter Text

Weeks.

That’s how long it had been since Prowl had known uninterrupted recharge. He hunched over his desk, head supported by one hand, and hardlined into his base’s network. His doorwings hung limp. A depth of exhaustion he hadn’t felt since his battle computer first roared to life. Now, like then, it wouldn’t shut up.

Certain words kept catching in its algorithm. They spiraled in recursive loops that felt like barbed claws digging into his neural net, scraping across and disrupting the privacy of his own thoughts.

He’d jolt online, spark racing, head splitting with pain as his battle computer kept dragging up the near-zero probability from the depths Prowl kept trying to shove it.

That nagging infinitesimal probability, flashing back every time he cleared it.

That Prowl was wrong.

A city in the Rust Sea could exist.

Did exist.

What if Sideswipe had truly come from this city in the sea, isolated from the rest of Cybertron since before the fall of the original Primes?

What if it had an energy source strong enough to power a shield that could withstand the storms?

What if it was the reason no one could fly over the Hexagon without losing power? Could its existence upend the war before it fully started? Tip the balance of power toward the Autobots, without Praxus taking a side?

The only respite Prowl found from the grinding agony cracking open his helm was to surrender: to run permutations under the assumption the city was real. Only then did the barbed claws recede. The frantic clamor in his head quieted to a low hum, allowing him to focus on his duties again as long as he set part of his battle computer aside to contemplate diplomatic contingencies.

Arranging the pieces of diplomacy like a tactical formation.

Himself as liaison.

If handled with precision, he could be the one who guided the allegiance of a myth.

The might of an entire city influenced by his command, just short of Vos’ borders. Its defenses and potential offensive capabilities enough to halt Starscream’s ambition, and Vos’ unchecked technological escalation.

The projections were so tempting. The solution. Calling to him.

He shook his head, resisting. The entire foundation was built on a speculative folly.

All hinging on two repeating, unconfirmed variables: that Sideswipe’s city within the Rust Sea existed, and it was technologically advanced.

The city would have to have advanced technology simply to survive in the Rust Sea.

At minimum, it had to have shield capabilities stronger than anything Prowl had ever encountered.

Because if Sideswipe’s city didn’t have a shield to hold back the destructive forces of the storms, it had to be subterranean, or armored in a material harder than fragging diamonds, or —

He shook his head again, the data cables hanging from his neck’s three ports tugging along his shoulder.

Prowl was not prone to ‘wishful thinking.’

It was a waste of time. Energy. Yet, his battle computer’s fixation made it impossible to ignore the profound sense of wrongness emanating from his prisoner. It was relentless. Obsessive. Trying to click some elusive logic about Sideswipe and his claims into place.

The transmission Prowl finally received a few days ago from the Archives in Iacon brought little clarity or comfort. Instead, the new information fueled Prowl’s existential dread that his battle computer was hallucinating: conjuring impossible notions, and connections.

The haunting fear twisted in his spark. Fueled a recursive loop of obsession. His struggles to recharge. What if his battle computer’s experimental algorithm was eating itself alive?

Just as it had with every single one of his batch-mates.

Save the one.

He shoved the memory away, suppressed the emotions, determined to never dwell on the chilling screams and muttered whispers of his batch-mates — peeling their way through their own armor to rip out off their doorwings, sensory networks, optics, and audials during recovery.

The only comfort to be found was in distraction. Not thinking about it. Riding his battle computer’s obsession out.

Thanks to the Archive’s response to Prowl’s query, new words now spiraled through his thoughts in addition to ruststalker. Stormsinger, and the city that ate the sky, in particular kept getting bumped to the top of his priority queue. Each phrase slowly loosening his grip on what he knew to be tethered in a logical reality.

He had thought he had read all the available texts regarding the Rust Sea prior to his deployment.

He hadn’t thought to check Sublevel Omicron.

The old vault, lit by the flickering light of half-decommissioned terminals, and archivists who seemed more alive surrounded by half-formed memory files than caring to exist in the present.

The data they sent Prowl was ancient. Most weren’t even files: scans of fractal-geometric etchings found within small, uninhabited, floating islands of Vos, of a mosaic mural entombed in a cave on the Praxus side of the Manganese Mountains — and a corrupted fragment of a memory file, extracted from one of the eerily displayed corpses inside it.

Myths. Legends. Stories.

Told in tiled pictures, and a dead, geometric fractal-based written language that burned behind Prowl’s optics, knotting his senses in a blur of impossible four, fifth, and sixth dimensional shapes as he tried to decipher it.

And essays.

Generations of niche academic dissection where each theory on the meaning of the mural entombed with corpses found at the archeological cave site conflicted with the personal opinion of the next.

Some argued it was a funeral rite. Others insisted they were ritual sacrifices made to beg safe passage through the Rust Sea to reach Vos. Even more fixated on how a corpse had been forcibly transformed to fit into a crevasse, and hadn’t been discovered until long after the rest were catalogued.

A preliminary survey of the data surrounding the decayed remains suggested to Prowl that the violence had not been ritual or methodical. Force vectors were inconsistent — too many fractures in non-lethal zones, too much redundant damage. Not the efficiency of a planned execution, but the chaos of an uncontrolled emotional outburst.

His building hypothesis was the bots in that cave were tortured. The injuries weren’t ritualist signatures, but deliberate cruelties.

Vicious. Sustained. And personal.

To Prowl, the cave containing the mural wasn’t a tomb. It was the site of a massacre — the remains of the oldest crime scene on record.

But the academics didn’t have his extensive background in forensics, or his battle computer parsing the evidence into probabilities. They hadn’t walked through rooms still wet and reeking of fresh energon, or sifted through files of cold cases until a pattern emerged. They couldn’t see the clear distinctions he did: when an execution was done in a controlled manner — and a slaughter born of rage.

They were all grasping for logic grounded in lost cultural practices. For ritual. For myth. But all their speculations were grounded on being reactionary. They wanted to ascribe deeper meaning to the remains within because the lead archeologist to discover it claimed to have found the only recorded evidence of a ruststalker.

A claim rooted in a degraded memory file, salvaged from one of the victims.

Once Prowl learned of it, that file was the next he opened. He was no stranger to sorting evidence surrounding murders. The gruesome crime scenes Prowl had analyzed during his time as an enforcer for Praxus had never interrupted his recharge. Energon splatters on the wall. Fried chips. Hollowed optics. Severed limbs. Gutted wires. Crushed spark chambers. It was all data. The pieces he needed to puzzle together events to reach a conclusion, concoct a linear timeline of events, and enable the wheels of justice ran smooth.

This video was different — affecting him in a way nothing else ever had.

For the first twelve seconds there was only audio: laboured, grit-choked fans straining to run, followed by gurgled screams that crackled as static in his audials. Then, for four terrifying seconds, the image cleared — and Prowl’s spark seized.

The first twelve seconds hadn’t been only audio.

The mech just hadn’t been able to see through the dense sand whipped into a funnel — inside the cave. But the victim could see now; could see the glowing red optics peering out at him from a swirling cloud of debris. Optics of red hot iron. A burning glare that was a mark of extinction itself. Dead. Inevitable. Already calculated. Not yet executed.

A silhouette of a mech emerged next, roughly formed — contrails peeling off any defined edge, sparks from its fin-like audial horns arced into lashes of cracked lightning.

Prowl swore he could feel the charge thrumming in his chest: rapid, staccato clicks of a fuse about to ignite a canister of compressed rage.

The silhouette raised a hand —

That was it. The rest of the data was corrupted. Decayed. Irrecoverable.

But the sheer brutality of the original report replayed on repeat in Prowl’s mind: the corpse this memory file had been extracted from, allegedly sand-blasted to facelessness before being gutted alive — doorwings dissected and pinned to the wall within the cave’s entrance.

‘A remarkably preserved specimen, all things considered,’ the lead archeologist had said.

That corpse was positioned so it was the first sight that greeted the archeologists from Praxus after they had pried open the sealed, cavern door.

Prowl’s lines ran ever colder with each successive rewatch of that file. A frigid dread seeping into every corner of his frame. An instinct sparked from that molten-iron stare captured from history, screaming at him to run. As if he had narrowly escaped this same fate. As if this horror had almost been his.

He could feel it pounding inside him, as sure as an unyielding vice grip had already been locked around his spark.

But logic overrode instinct.

There were thousands of other explanations to this file other than evidence of a ruststalker — and piles of academic arguments in Prowl’s favour that he was not, in fact, holding one in his make-shift brig.

No matter the haunting parallel to how he had first seen Sideswipe emerge from the rusted-dust storm on the landing platform.

After all, it was difficult to trust a corrupted memory file, dated to a more primitive Cybertron — a time when sparks were haphazardly kindled during merges, not forged to full function.

A more violent time. Where the impulses of barely socialized blanks ran rampant without the structure of society to curb them.

Cybertron, as it was painted in the days of titans, demi-god heroes, and Quintesson monsters — before rationality and science imposed order and made them architects, masters of their own destiny and design.

Reality.

Neatly quantifiable, and explainable.

These past few days, any free moment he had, he studied the mural found at the archeological site, as he was now. The mythological Quintessons were clearly at what was considered the beginning of the mural. As was a hexagon containing two triangles within it. A yellow one pointing up, a red one pointing down. But overlapping into the figure of a six-sided star. The shape was surrounded by a star map, but despite Prowl’s attempts, it was impossible to align a recognizable patch of sky. The leading theory was massive stellar drift had occurred between the mural’s construction and the present.

It was clear the depicted two-dimensional shape was in reference to the Hexagon ever-storm that raged over the Rust Sea. Though no one had been able to conclusively prove what star sector the star map referred to.

Still, Prowl allocated part of his battle computer’s processing power to work on it. It was his hope that if he could align the constellations, it could lead to reliable co-ordinates for Sideswipe’s city.

From there, everything spiraled. There were just so many conflicting myths, and dissections of them, to sort through.

One account the Archives had from the etchings of Vos, translated from the long-dead dialect born of impossible geometry — if the translation could even be trusted — said the mighty power of the city that ate the sky crushed the quintessons under heel and wheel, and in the process went mad. Forcing the mountainous region of Vos to flee. Rising beyond its terrifying reach.

A fringe theory said the city that ate the sky and the mythical lost Crystal City were one and the same.

Even more conflated the entities referred to as the stormsinger and the ruststalker into one and the same being. Others insisted a ruststalker was a corrupted form of a stormsinger. Corrupted by turning its back on its duty, and using its powers for personal, selfish reasons.

Both beings were said to appear in the mural: repeating red and yellow mechs spanning tiled representations of time.

A stormsinger was described as a guardian — though the translation felt wrong in ways Prowl couldn’t define. So, he pushed his battle computer to learn the geometric, fractal-based dialect directly, intending on doing the translations himself.

Patterns kept arising between ruststalkers and stormsingers — patterns his battle computer fixated on: both mythological beings walked on tornados, rode lightning, and sang in the fractal resonance of crystals. They unlocked vibrations that confused and influenced a mech’s spark through the lattice network of a spark chamber.

One to lure victims into their storms to be devoured.

One to sing the pathway for the lost back out.

It all sounded like pseudo-sciencfic superstitious nonsense.

But Prowl conceded that the imagery of “devouring” could be interpreted as the sand-blaster effect of debris in the wind — myth layered over environmental safety hazard.

And he would have left it at that rationalization — fixating instead cross-referencing: the city that ate the sky, titan legends of fighting Quintessons, Crystal City myths, storm patterns, wind movements, star charts, translations, satellite data. Anything to triangulate a possible location for a city within the Rust Sea that would make his battle computer shut the frag up —

If Sideswipe’s lyrical voice hadn’t kept bleeding through the vents, interrupting his focus.

There was no logical way Prowl’s prisoner could know the brig’s vent system fed directly into Prowl’s private command quarters as a security fail-safe.

He knew that.

But logic couldn’t explain how often Sideswipe casually displayed knowledge of conversations throughout the base while he remained confined. Nor did logic explain Sideswipe’s uncanny ability to break into song the moment Prowl’s guard slipped, when his systems, exhausted and vulnerable, dared to seek a moment of quiet to process information.

It was as if Sideswipe could sense the precise fracturing in the war between Prowl’s neural net and his battle computer, and sang to prying them open with his thick, worn fingers.

“Hush,” Sideswipe’s current song resonated out of the vents in a low, haunting dirge. “She walks. She stirs the sea. She sighs. The winds, they howl and flee. She calls. Her speakers answer. Singing her path. Hush. Do not speak of her when the wind is high. Hush. Or you may draw her vengeful side.”

The last part made a cold prickle of static creep up Prowl’s spinal strut as his battle computer locked in on the hunt, yanking Prowl’s consciousness with it. He needed to verify it. Now. He tore through the Archive files again. That particular phrase, slightly altered, was there. Scrawled in an archaic version of formal Praxian across the sealed chamber door of the mural massacre site outside Praxus.

Do not speak of it when the wind is high. Erase its name from memory. From record. From your lips. It listens. Walks among you.

It will draw near. Vengeance and chaos will unleash.

Devouring all in its path.

Beneath it: a crystal mosaic mural. A spindled creature of black crystal, with far too many legs for Prowl’s comfort, striding upon rust-red tornados. A crown of antennas bent like horns called forth lightning, blasting mountains made of crystals to pieces.

Behind it sprawled a crystalline growth, and if Prowl squinted, he could see a resemblance to Praxus’ gardens.

Vos, and its fragmented mountain range on one side. The creature baring the mark of the hexagon and the six-sided star within. Then Praxus, represented by its gardens.

In the centre of Praxus, a tall crystal was being struck by lightning, and on that lightning bolt rode the figure of a yellow mech. Prowl’s analytic focus snapped back to the monster. The Rust Sea. Within it, another small figure stood, barely formed into the tiled shape of a mech, it was so tiny.

But it was red.

Spark racing, he compared the crystal mural on the door, to the mural massacre site found inside.

The materials of that were different, but the subjects were similar.

Within the cave, the spindled monster recurred through time, walking on tornados and hurling lightning — always containing either the red or yellow mech inside it.

But it was the tiny blue-green tiles that drew both his neural net and his battle computer’s focus.

In both the crystal mosaic and the metal one, the yellow and red figures optics had been made out of small tiles of copper.

Copper, that had oxidized over time to preserve the tiles.

Patinated, over the ages.

The realization snapped the other materials used in the cave mural into a grim pattern.

The two figures. Iron-oxide red and uranium-oxide yellow. Rust and urania. There were always two figures of those colours. Painted as deadly oxidized metal and decay. One riding lightning or within tornados, and the other with the monster that wore a crown of lightning, holding a tear in the sky or holding back Quintesson monsters.

The positions of the red and yellow mechs would switch throughout the mural’s timeline.

But they were never depicted together.

That seemed — felt — important.

Prowl had no idea why it stood out to him, or what it meant.

He sat back, examining the colours that were used. The materials in the mural’s analysis. And how they had decayed over time.

Decay.

All oxidized decay.

The green and blue patina of copper. The purple, blacks, and brown of manganese oxide. The white powdered rust of zinc. Of iron. Red, brown, black — and even yellow. It wasn’t just uranium oxide. Iron could oxidize yellow.

Oxidization that occurred at a higher rate because when lightning split oxygen molecules —

Every tile in the mural was a tone mirroring the hues found in the deepest, northern most dunes, visible only from orbital scans. This mural was constructed from material found beyond the boundary line in the Rust Sea.

By someone who carefully selected each and every tile, knowing exactly how the colours of decay would emerge over long periods of time.

By someone who had lived there.

From there, a new realization clicked into place. Every hue, every stain of colour on Sideswipe’s frame was in this mural. It was less like an influence, and more like a direct echo shouted across eons. A warning. Meant to intentionally set mechs on edge.

A living palette of decay walked among them.

The shape of a pattern formed out of permutation, not of logic, but of feeling. A recognition dancing in the corner of Prowl’s HUD, summoned from his battle computer.

An anxiety. A thrill. A deep longing entwined with an aching grief, all circling a ragged edge of what felt like a faded, brutally severed connection — a phantom limb Prowl couldn’t access, but knew with certainty should be there.

Her split speakers. They’ve come to —

Shattering as the hypnotic resonance of the song in the vents shifted.

Into the tune of a crude drinking shanty.

“Oh Sunny — so bright and shiny.
Showing off your hinny.
Stop being so whiny —
You’re such a meanie.”

The last line didn’t even rhyme.

Grinding his back teeth, Prowl slammed the ancient scans and translations he was slogging his way through onto his desk. He ripped the data cables out of his neck. Fists clenched tight, he stormed out of his quarters toward the brig, intending to silence his prisoner.

But the moment he crossed into the holding corridor to the cells, and he saw him, his words simply failed.

Sideswipe was singing: leg propped on the desk in his cell, a damp cleansing cloth in hand. He dipped it into a shallow basin of cleanser, then dragged it up his zinc-oxide painted thigh. Suds traced his ridges and pooled in narrow rivulets — a path Prowl’s battle computer tracked, meticulously.

Every. Single. One.

Overriding all else.

His vocalizer failed; there was no room left in his head for anything as coherent as words. He averted his gaze. Fixated instead on the puddle forming beneath the desk, trying desperately to make space for a single organized thought amid the chaos his battle computer was scribbling through his mind.

“I’ll…” he rasped, the word a dry, crackled sound, echoing off the metal walls, reverberating like feedback through his head. He cleared his vocalizer of the painful static, managing a strained whisper, “come back later.”

In the hastily assembled brig not meant for prolonged use, it suddenly occurred to Prowl he hadn’t thought to arrange washrack access for Sideswipe these past weeks. His cooling fans clicked on as his face heated at the obvious oversight.

“Why?” Sideswipe asked. He tilted his head, his sculpted cheek beneath his strange optics catching the light, and Prowl’s gaze rose again, trapped in a magnetic pull of the copper swirl born of the ages found there. “I could use the help getting my back.”

Peripheral vision greyed out as Prowl stared, his fans whirring louder as if his body was being tugged under a magnetic current. Sideswipe’s optics pulled him in, and held him. The files Prowl’d been sorting and translating jumbled in a heap as they piled over each other in his mind. Willfully, he ignored the flashing subroutine of his traitorous battle computer still parsing the slow, deliberate drag of suds along thick thigh plating.

It was too hot in here. Wasn’t it?

Prowl pulled at his collar-faring as air gusted from his vents, setting a warm brush of wind against his neck’s sensors. A shiver ran through him from the light touch. Why was it so hot? Had the airflow reversed again? He swore he had ordered maintenance to fix that.

He tore his focus away from Sideswipe’s unblinking stare, and scowled at the fan.

“What is wrong with these vents?” Prowl muttered.

Sideswipe leaned forward, dipping the cloth into the basin for more cleanser then shrugged, humming as he dragged it up his leg — all the way up to that stamped imprint, that little line with the triangle pointing down, and lingering there to clear the build up in its crevices — leaning back, then wringing the cloth out over his chestplate.

“… now that you mention it —” his tune dropped lower, and a moment later the fan above them spun to a halt, then started up in the other direction.

Hot, outdoor air assaulted Prowl’s face, carrying with it the faint metallic tang of the oxidized landscape outside in, making his head swim.

As the blast of heat washed over his sensors, the room distorted and Sideswipe’s edges shimmered.

Prowl’s mind clawed for an anchor. The archives, the mural, the corpses, the memory file —

The warning on the sealed chamber’s door.

His battle computer cleared them from his queue, fixating on that sudsy little triangle pointing down.

Two triangles within the hexagon combining into a single star. Red and yellow. The triangle pointing down was always red.

And he took a step forward, energy cuffs already in hand to transport Sideswipe —

He paused, frowning at the cuffs he didn’t recall pulling out of his subspace, then back up at Sideswipe — who stepped to meet him, movements as light as a seeker taking flight. Sideswipe leaned one arm above himself over the threshold of the cell’s glowing pink energon bars.

“Useless as try to bind wind?” Prowl asked, struggling to use the syntax of the dead language he’d been teaching himself from the Archives’ translations.

Sideswipe shrugged, the saturation and hues in his optics glinting in an amused, mostly blue-green light, responding to Prowl’s butchered attempt at his language by using an outdated form of formal Praxian, instead of Neocybex. “If they make you feel better when handling me, and you’re creative with their use, I don’t hate the look…”

“How do you keep removing them?” Prowl asked, dusting off his own formal Praxian files.

“Simple,” he hummed in the dead language. “Correct harmonics.”

Prowl stepped even closer to listen. His attempt to speak it, in comparison, sounding flat and lifeless. The language’s spoken syllables were like the harmonics of a singing crystal or a string once flicked — of warbling notes, not only of the known twelve chord scale, but including ones that existed in the space between them. It —

The glowing pink in front of his face snuffed out. The energy bars to the cell dropped. Deactivated.

Startled, Prowl stared up at Sideswipe, bracing for him to lunge forward. Break free.

Sand blast off his face. Consume his internals to replace the greedy, rusted decay inside himself.

An attack never came.

Just a slow, easy, infuriating smile spreading across Sideswipe’s face as he sank deeper into his pose against the threshold. One that deliberately showed off the seams between his segmented abdominal plates…

To clean, unfrayed internal wires and joints underneath.

“If I wanted you dead,” he teased, in formal Praxian again. “I would’ve let that piece of scrap decapitate you in your courtyard. Easier.” He shifted back into his musical, very alive, multi-tonal, and deeply harmonic language. “Why do what the wind will give for free?”

“What do you want?” Prowl asked in a clipped tone, dropping all pretense that he had any control over this mech as a prisoner.

Why are you here? Why reveal yourself now?

The questions clawed at Prowl’s vocalizer, left unsaid. His battle computer parsed a forgotten civiization with an advanced technology. His mind said he didn’t have enough data, highlighting the warnings surrounding ruststalkers and stormsingers from myth.

Which one was he dealing with? And was there even a difference between them?

“Right now?” Sideswipe leaned into the space between them, narrowing it. The hot curl of his vented air traced Prowl’s neck cables in tiny, wandering fingers of swirling eddies. “A personal escort to that shower of yours you used late last night would be nice.”

His words stirred currents that licked up beneath Prowl’s armor, tracing the sensitive inputs and circuits within his doorwings — carried by a playful, teasing magnetic breeze.

Prowl stood locked, motionless, suppressing the shiver of warmth flaring beneath his armor as the reversed ventilation shafts sent flickers of heat across his bumper. His battle computer spun through combat protocols: none of them relevant.

There were no logical suggestions for what to do when a monster of myth and legend invites itself in for a shower.

All the legends ever said was not to listen to its song. To turn and walk away. Don’t let it draw a clear path into its storms.

Or be swept up, and devoured.

Prowl had to keep reminding himself he didn’t believe in supernatural superstitions, but he did believe in patterns of observation.

And right now those patterns pointed to Sideswipe having some manner of technology Prowl was unfamiliar with. He was using it to disrupt their cuffs. Their air vents. To listen in rooms he wasn’t in.

To disrupt the cell door’s bars.

A lost technology.

Had Sideswipe disrupted their power generators for their shield when on the landing field? Was that the frequency Prowl had detected as off pitch when the wind picked up?

Power.

It lingered in the air, tasting faintly of ozone. Of a tinge of copper clinging to the back of his throat. It brushed along his plating, creeping into the seams of his armor like corrosion spreading unseen. A static. The first speck of rust in a fracture line. A pull of a magnetic field he couldn’t repel.

Power.

Sideswipe had it swirling all around them, seeping through them, and they couldn’t even see it. He’d been toying with them these past weeks from the brig. Laughing at them. He could leave whenever he wanted.

He knew it.

Now, for some reason, he wanted Prowl to know it.

That conclusion had become undeniable. Become reality. A ripple of charge spread through Prowl’s lines, coiling tight along the connections between his spark casing and his neural net until it almost ached, as if something inside him was writhing, straining to answer an alert.

A call.

A tantalizing temptation.

A solution presented to him by his battle computer. Unbidden, but it dug into him all the same: Prowl could outwit the veil of myth and mystery shrouding Sideswipe’s sudden appearance.

Control the information he learned of current events to guide him to Prowl’s side.

Tether him, and his powerful city, under Prowl’s influence, not the Autobots’ —

For his own ends.

For Praxus.

Chapter Text

The cap on the bottle of hi-grade hissed as Prowl broke the pressure seal. Argon gas spilled over the neck, curling over Prowl’s fingers in pale wisps. The gas was chased by bubbles rising from within the citrine fuel, their effervescence catching the light like captured starlight.

Prowl sniffed at the rim — the fumes burned the inside of his nasal passage, but beneath the sting was no acrid sign of spoilage.

Good. No excuse not to continue this path.

With a hand steadier than his spark’s pulse, he poured into a pair of clear crystal tumblers.

One for himself. One for his…

Guest.

As he tilted a tumbler toward the tall, arched windows behind his desk, his grip slipped.

In the valley below, two towering tornados twisted about each other — their magnetic winds charged to opposing polarities. Orbiting, their debris fields colliding, but the core of them never touching. Dancing in a way, as their charges repelled each other. He watched for a few moments, hypnotized by their procession along the ridge of a storm-lit red dune. A thin, narrow funnel dared to cross their path. They surrounded it. Trapped between them, the smaller funnel was quickly overwhelmed — shredded, its pieces shared without ceremony.

Prowl swallowed around the sudden tightness in his throat. He told himself it was nothing he hadn’t seen before over the sea, and that was true. His battle computer didn’t care. It saw a pattern in it. An ominous foretelling.

Her split speakers. They’ve come to — the action line cut off.

That same frayed, severed place again, a static-laced ghost signal. A new and uncomfortable sense. Eager. Terrified. Anticipation. The sense of those emotion all existing as one.

Attempting to complete the sentence was akin trying to move a finger that wasn’t there.

He suppressed the sounds of his batch-mates threatening to rise in his memory. Of the ones who struggled to stand and walk without their doorwings. The ones who tried to lift a cube of fuel with an arm they had ripped from their frame, and left in another room.

“This is what I get for feeding it garbage,” Prowl muttered under his vents, shoving that action line far to the depths of his battle computer’s queue.

He had been drowning every free moment of his consciousness in the myths and legends surrounding the Rust Sea to appease his battle computer’s obsession. It was exhausting. There were so many reasons why that recurring line meant nothing. The phantom sensation meant nothing.

What mattered was filtering intel from myth to pursue the correct course of action, and open relations with Sideswipe and his city.

He could not ignore this opportunity. This spread of enticing new variables.

He lacked the reputation and the rank to gain an audience with Optimus Prime. Prowl’s dire predictions surrounding Vos — about Starscream, his ambition, his intelligence, the reports of the elusive teleporter he’d pulled into his trine — none of it was reaching anyone who respected Prowl’s assessment. None of his warnings were reaching Autobot High Command.

And Praxus’ council wouldn’t listen, despite Prowl being their only success from the Tac-Net Program.

They preferred to pretend the rest of it, the failures, had never existed.

Trying to explain his capabilities to the Autobots had been for naught. They wanted him to prove it. Distinguish himself.

They were all wasting Prowl’s time.

Praxus’ time.

To date, only Datarider — a signal operator from the enforcers — and Smokescreen had believed Prowl’s grim predictions of Praxus’ future, and what it meant for all of Cybertron. Only they had joined him to enlist in the Autobots to try to prevent it.

And now, a new dangerous variable offered promise. An accelerated path, impossible to ignore.

Prowl averted his optics from the tornados, before swirling the citrine liquid within the tumbler, giving it a moment longer to adjust to the new atmosphere.

Let himself adjust.

Not to the high proof fumes already rushing through his exhausted systems, but to the vacuum Sideswipe’s presence left behind; an afterimage in the way air moved around the room.

Around him.

Prowl had gotten quite good at strategically impressing a target with ceremony. At navigating the diplomatic aspect of promotions. Greasing the right wheels. It had landed him this command. Smokescreen as his second, and Datarider recalled from installing comms towers on the outskirts of Kalis.

The Autobots were keen to recruit more Praxians. For their allegiance. Prowl had used that, all while knowing the council was committed to their independence. Their neutrality.

Whether ceremony would influence or impress Sideswipe remained to be seen.

Sideswipe’s formal Praxian was fluent, though its antique accent bordered on mockery — yet, better in some ways than Prowl’s own.

How much did Sideswipe truly know of Praxus? Would Sideswipe understand why Prowl chose these specific crystal tumblers, or vintage? Would he understand what was being proposed by Prowl serving him?

If Prowl had any hope of making this alliance work, the signal of his command mattered.

The signal of his power mattered.

He needed the legendary city that claimed the Rust Sea to want to deal with him — and only him — before he reported its existence to Autobot Command.

The surface in the crystal tumbler rippled, interrupting his thoughts. Prowl blinked at it, then turned to look at the one still sitting on the table in front of his couch. He reset his optical sensors again. The pattern in the surface was still there. In both tumblers.

Through the walls of his berthroom, percussion thudded, rattling datapads on his shelves. A wordless gritty-industrial beat, a vocalizer descending into static and rhythm.

Sideswipe sang in the shower, infusing the small, utilitarian stall with life.

The part of his battle computer Prowl’d allocated for translations of Sideswipe’s language tried to make sense of the geometric shapes forming on the liquid surface. Prowl’s grip tightened on the tumbler, unconvinced he wasn’t hallucinating a coherent pattern in it. He set it gently beside the other before he broke it, then clasped his hands behind his back.

He resisted staring at it as he clenched his hands in and out of fists.

Irritated.

Prowl didn’t like how Sideswipe kept making him hesitate.

He wanted to run. He wanted to stay.

A part of Prowl still feared his battle computer consuming his mind. That its patterns weren’t evidence at all, only hallucinations — leading him toward this fascination with Sideswipe he couldn’t shake.

Another part of Prowl feared it wasn’t.

And that fascination, that magnetic pull he felt toward Sideswipe, was his own.

It had to be Sideswipe’s unflinching confidence. He made everything look easy. Prowl found that trait admirable in a mech — attractive even.

Sideswipe filled a room, leaving no space untouched. Even here, in Prowl’s private quarters, it felt as if Sideswipe had already staked his claim on it.

Making Prowl feel as if he were the intruder.

Sideswipe’d done the same in the corridor. Unbothered by the stares as Prowl escorted him, unbound and without explanation — all while Sideswipe strut out in front of him, humming a low skirl like he had already mapped the way.

Not a single moment since Sideswipe’d been brought into the outpost had he wasted it on uncertainty. Not even here, in Prowl’s private quarters.

Was it all because of a massive power imbalance between them?

Why wasn’t Sideswipe at least a little bit nervous? Why did he act as if nothing Prowl, or those under his command, could do would harm him?

It was as if the entire outpost had become his stage, and all — except maybe Prowl — were merely his audience. Faces that blurred together. Not worth processing beyond a mass of gasps, static, or applause.

Prowl shook his head to dispel the strange feeling crawling inside him, shifting the tumblers on the table until they were arranged to match an exact symmetry.

Re-centred.

He was in control.

This was his command. His outpost network.

… erected on the shifting-sand shores of Sideswipe’s city — that legend told was powerful enough to send Vos fleeing into the sky.

Once Prowl would have called that absurd. Stories from primitive minds grasping to explain the nature of storms in the Rust Sea and the flying mountain terrain —

That flew in segments; as if the mountains had been shattered before taking flight.

Prowl had to know. What could be powerful enough to shatter a mountain range into fragments —

Lightning. Like that of the spindled creature etched on the cave’s seal outside Praxus. A weapon that flashed like lightning.

Prowl picked up his tumbler again. Fiddled with it between fingertips. Watching the sound patterns from Sideswipe’s deep thrumming form on the surface.

There were always two in the mural. Red and yellow. Rust and urania — both states of oxidation, both decay. One triangle up, and the other down, overlapping into a star.

He was dealing with the red one. Pointing down.

What did that mean?

And if he could twist Sideswipe to ally with his command, what did it matter, ruststalker or stormsinger, which he dealt with?

It mattered when he thought of the memory file extracted from the site of the mural massacre.

His comms crackled, Smokescreen’s voice coming through. “You’re certain, it wasn’t a mistake to let him out?”

“He demonstrated to me that he could have escaped that cell whenever he wanted these past weeks,” Prowl answered. “We are in no more danger now, than we were from him before.”

“I wasn’t really thinking about the collective “we,”commander,” Smokescreen said. “I meant you. Alone. With him.”

“He speaks a dead language from the Archives. Until proven otherwise, I have reason to believe he is a diplomatic envoy —”

“Then at least let me —”

“I am in command here,” Prowl said, putting an end to the call.

He understood Smokescreen’s concern, but command meant he didn’t have to justify himself. Not to Smokescreen.

“I am in command here,” Prowl said again, this time out loud.

His battle computer answered — clocking how Prowl hadn’t offered hi-grade first before showing Sideswipe the washrack. How he hadn’t made him stand in discomfort as Prowl forced him to stand on ceremony and civility.

And now, Prowl stood in his receiving area, alone. Waiting, on Sideswipe’s timeline.

How had that happened?

Was Sideswipe truly so powerful it seeped from his every seam? Warping Prowl in deference to him?

As Prowl glared at the wall, the one-mech performance in the washracks abruptly stopped.

In the silence, Prowl caught the sound of cleanser running over armor, carrying its own enticing rhythm. His battle computer flagged a rise in temperature that had nothing to do with the fumes of the hi-grade —

“Traitor,” Prowl muttered to it.

“Commander…” Sideswipe called in a long lyrical drawl. “I could still use a hand or two with my back… ”

Prowl’s jaw tightened as his doorwings flared high and wide outside of his control. He returned the tumbler to the table with a solid thunk. Careless, he could have shattered it.

How was this mech making him so careless?

“There’s an extender in the corner,” Prowl snapped, loud enough so Sideswipe could hear him over the spray.

He didn’t hide his irritation with Sideswipe — with himself — from his tone.

For a moment, only silence came in response. And somehow, silence coming from Sideswipe seemed more ominous than performance.

“This thing?” The extender was shoved around the corner of the doorframe and the claw on the end of it clicked together.

Which meant… a low rumble escaped Prowl’s engine as he strode across his private office, knocked the extender out of his way, rounded the corner, and pointed.

“Stay in the washrack until you dry off, you’re dripping everywhere and getting suds all over my floor!”

Sideswipe just shifted in his growing puddle and grinned at him — then tilted his head and deliberately clicked the extender in Prowl’s face. “You really use this when you clean your back?”

“Yes.” Prowl pushed Sideswipe backward. “Get.”

As Sideswipe retreated, still looking curiously at the extender as if he’d never seen one before, he clicked it repeatedly by pulling the trigger until he found a rhythmic beat he liked for it. His industrial heavy metal concert began anew, this time with the extender’s clicks as accompaniment. He turned around into the spray so it hit his back and moved to the beat of his own music.

“That’s not —” Prowl rubbed at the base of his chevron. “You need to attach a cloth to —”

He was interrupted by a prompt from his battle computer — suggesting this was a more relaxed, diplomatic opportunity.

Prowl hadn’t planned for opening negotiations for access to Sideswipe’s city to happen in his washrack.

But…

This wasn’t about comfort or dignity — of which it was clear Sideswipe operated on a very different scale. It was about momentum. Control, and taking it back. Nothing else. Certainly not about the way Sideswipe’s wet worn armor gleamed under the spray, or how the steam caught in the dips of his armor, caressing down him as if the mech was sculpted from wisps of shadow.

Stop it.

Prowl tamped the thought down, hard.

Focus.

“Turn around,” Prowl said, more confidently than he felt as he grabbed a cloth. “It’ll be more efficient if I do it.”

And stepped into the small space with his…

Guest.

Sideswipe liked it hot.

Steam curled against Prowl’s armor, hitting his vents like a living wall of humid heat that seeped into the seams of his exposed joints.

Prowl flared his doorwings flat and wedged into the narrow space and immediately regretted it — not for tactical reasons, but because his washrack was too small, too warm, too wet…

And way too close.

Sideswipe didn’t look back as Prowl joined him, just stood beneath the spray, optics shut, humming softly to himself. He bowed his helm, the spray of cleanser pouring over the aerodynamic curves of his broad back. Small falls of the sudsy rust treatment dropped from the bottom lip of his armor, running down his exposed plated spinal strut that dipped along his low back and disappeared into —

Prowl’s battle computer re-prioritized three 'relaxed' diplomatic questions to the top of its queue. He ignored them all, like he ignored the way Sideswipe’s thick, black pelvic armor hung over his hips as if threatening to drop off.

“How do you normally clean your back?” Prowl asked, hating the way he sounded — so obvious he was pretending not to be interested.

Sideswipe’s heavy shoulder plating shifted, lifting his back armor a little higher, exposing more of his spinal strut as he shrugged. “Sunny always ambushes me the moment I return.”

Sunny, again.

An insidious stab of jealousy bore into Prowl’s spark. The cloth, weighted with cleanser, pressed harder over the rusted-grime clinging to the sloped ridges of Sideswipe’s armored spine.

What was he doing? Why was he jealous? With conscious effort, he softened his touch.

“Return… home?” Prowl asked, dragging the cloth down the curve of Sideswipes shoulder and into joint exposed by his shrug, with as little expression as he could manage. “To your city? Rusty?”

Primus, it sounded so ridiculous hearing himself say it out loud.

His doorwings were spread along the wall behind him, rigid. He forced his optics to stay fixed on his task, even as he kept logging unnecessary details. The way the rust-streaked acid-based cleanser trickled down the exposed white of Sideswipe’s stained thighs. Prowl’s vision swam. The heady scent of burnt copper, ozone, and Prowl’s own sweet gun-oil scented cleanser — that his battle computer tracked, pooling along the grooves of Sideswipe’s abdominal seams — combined with the heat, making it hard to focus.

“Yeah,” Sideswipe said, armor relaxed as he shifted his weight on his hips, created a gap at the top of his pelvic guard, exposing a place Prowl could look straight down into. “That’s where Sunny always is when I go roving.”

Sunny: who likely sported a yellow paint job, patina-copper optics, and had an engraving of an arrow on him pointing up.

The stifling humidity clung to the back of Prowl’s intake as he swallowed. This could be confirmation. The murals. The two figures. Never depicted in the same place at the same time. His spark pounded. “You two never leave together?”

“Can’t.”

The word escaped barely parted lips, sinking in the heated steam along with Sideswipe’s shoulders, as if Prowl had pressed against an old wound that could never heal.

“Why not?”

Sideswipe didn’t answer. He leaned back into the spray, letting the cleanser cascade across his chest while he dragged both hands up his audial horns. It was impossible to ignore how the motion arched his back, consuming the scant gap between them as he rested against Prowl’s bumper.

“You’re being purposefully evasive,” Prowl said, sharp with irritation as his hand holding the cloth was trapped between them.

“I’m being mysterious,” Sideswipe said with a smug glance over his shoulder. He turned, towering over Prowl and resting his forearm on the wall above him. His other arm stretched out, fingers trailing through the rolling steam, skimming along one of Prowl’s doorwings. “You love mysteries, don’t you?”

A shiver of charge rolled from the direct touch to his sensitive scanners, down Prowl’s spine. His lips parted slightly, a tightness constricting his throat.

Confirmation. Conclusive confirmation. Sideswipe had heard the conversation between Smokescreen and Prowl outside the processing cell. How? Prowl didn’t know. But Sideswipe was letting Prowl know he’d heard it. Giving him another glimpse of the strange power he held.

“Why are you here?” Prowl asked in a whisper that drew Sideswipe closer.

“To re-open relations between us,” Sideswipe said, vents ghosting against Prowl’s frame in a returning whisper. “My city and Praxus were lovers once.”

Prowl’s battle computer shuddered. Went blank. Queue cleared.

The washrack walls were distorting, too small, closing in. It echoed in here, too loud. Steam and pressure hissing out of tempo with that low hum to Sideswipe’s words. His thoughts slipped loose from their moorings, drifting toward the wrong sensory inputs.

On the verge of a crash, Prowl's joints locked as his battle computer alternated between being blank, and tracking too many inconsequential details.

“With your presence here,” Sideswipe continued at a whisper, “fingering your soldiers along my city’s shores, her temper has cooled and she longs for his company again.” Heat pressed in around him. A knee slipped in between his legs. A roll of pressure. A vibration of a purr. The scent of burnt copper and ozone from a building lightning strike seeping into him. The static-buzz of charged proximity racing through every circuit. “She forgives Praxus his trespasses with Vos. It is her hope that through me, the spark they once shared could be rekindled, Commander.”

“You don’t have to call me Commander,” his entire frame heated impossibly further as the words tumbled out.

“It’s what you’re called.”

So Sideswipe didn’t know everything, only what he heard said out loud within the base. Prowl fixated on that observation, clinging to it as an anchor to steady his battle computer's loose moorings.

“To my troops,” Prowl said, testing the boundaries of Sideswipe’s power.

Sideswipe’s optics darkened, the playful blue-green swallowed by reddish brown. The heat in the air pressed in against Prowl’s throat. Taking form. An almost solid weight. “I am not one of your toy soldiers.”

“Good.” Prowl raised his chin in defiance of Sideswipe’s sudden shift in mood, and the pressure applied to his neck. “If you were, what we’re doing’s against regulations.”

That seemed to appease Sideswipe. His expression softened again and the copper-blue tinge expanded through his optics. He leaned ever closer. Lips grazing the side of Prowl’s chevron.

“And what are we doing?”

“Re-opening relations between our cities,” Prowl turned his head slightly to keep Sideswipe in his sights. “Proper introductions are in order. My name. It’s Prowl.”

“Prowl?” Sideswipe said slowly, pulling back as if testing the full-bodied taste of its shape on his tongue. “Prowl,” he repeated, finding its melody as he elongated it in an oscillating purr, then smiled. “A clever draft that sulks through cracks, seeping in with seeking tendrils… ” He leaned forward again, trailing the backs of his knuckles from Prowl’s doorwings to drift down the side of his chevron. “Prowl,” he repeated in that same purr, optics distant, as if scrying divine meaning in the vibrations it formed in the narrow gap between them. “A little zephyr, hailing from the northwest, heralding the change in seasons.”

“If you say —“

“I do say. Feels good stirring the air around me,” He refocused in, his optics ignited in a smoldering, red glow. “And in my mouth.”

Prowl’s spark flipped in on itself, charge racing through him. He parted his lips, feeling a gust of Sideswipe’s own vents entering him. Wrapping like cables beneath his armor. Tilted his helm into his touch.

The blue light of his own optics caught on Sideswipe’s fangs, and suddenly Prowl was seeing him again. The edges of him indistinct like the memory file recovered from the mural massacre site. A monster taking the shape of a mech in rust-churned winds — optics on fire —

Drawing in prey with pretty songs —

Fuel pump pounding, Prowl ducked and weaved beneath the arm blocking his exit.

Sideswipe blinked, surprised flitting across his face. His optics followed Prowl’s retreat, his mouth parting in confusion as he watched Prowl slip through the small gap like vapour.

Then his lips spread into a wide grin.

He stepped from the spray, his scarred armor gleaming as steam rose from his frame. Droplets clung to him before giving way in trickles sliding down, tracing the topography of him. He grabbed a towel from the rack and slung it over one shoulder, letting it hang as he hummed a low bass line with his engine. The notes reverberated through the air, making Prowl’s crystalline spark chamber thrum in his chest.

“You think I don’t enjoy a little slip and slide around a tight curve in a chase?” Sideswipe’s engine simmered from its deep bass into low purr.

“Some of my soldiers are convinced you’re a ruststalker,” Prowl blurted, the words coming from him without thought or calculation.

There, he said it.

That stopped Sideswipe, his grin to twisted downward.

The windows to the balcony rattled behind Prowl as Sideswipe reared back, scowling. “A ruststalker?”

“A superstition that gets passed on to new arrivals to keep them from wandering into the sea,” Prowl explained, panic flaring as he realized his misstep had led to insult. “Stories of a monster akin to a spark-eater, one that lives in the storms. Unlike a spark-eater, it doesn’t stalk its prey. It screams and sings to lure its victims in close before devouring them to keep its rotting, rusted frame from consuming it.”

For a moment, Sideswipe said nothing. A glint flashed across his optics and he tilted his head. Unblinking, his gaze slid down his own frame, lines of sudsy cleanser still running in graceful streams. The calmer colour returned to his optics as he toweled the side of his helm, then his throat.

Slowly.

“Is that what they are saying about us these cycles?” He muttered, lifting his arm to sweep the towel across his chest, revealing the cut of his abdominal seams. The motion pulls his armor taut, his finish storm-worn — “Do I have signs of rust rot in me?”

But clean.

“No.” Static caught in Prowl’s vocalizer as he tried not to track every droplet that trickled into the curve of Sideswipe’s hip, spilling over to trail down his prominent pelvic guard and the engraving there. “No, you don’t.”

“Rotting, rusted frame —” Sideswipe laughed low, a sound like thunder rumbling along a distance ridge. “Sunny would use me for target practice.”

“I shouldn’t have —” Prowl began, embarrassment flushing through him. How could he have spoken so carelessly? “I apologize, I —”

“Apologize? Don’t.” Sideswipe waved his hand, stepping in close again. He dabbed at the suds still clinging to Prowl’s chevron, the touch of the towel unexpectedly gentle. “You’re afraid of the ones that live in the storms. How charming.”

Prowl’s doorwings shot upright. “I’m not afraid of something that doesn’t exist.”

“Did I say they don’t exist?” Sideswipe said, tone dropping, hushed. “It’s good advice, to stay away from the sea. The winds tempt. They carry whispers and promises.” He circled behind Prowl, towel slipping down across his bumper. He reached in to drag it across Prowl from behind, his words a susurration of rust-strewn dunes. “You can make it, they whisper. You can do it.” He moved the towel down, caressing it across the narrow point of Prowl’s waist. “They twist and they turn. Tie you in knots. Until you’re lost. Dizzy. Disoriented. Sucking mechs in —”

Prowl vented sharply as Sideswipe’s tongue pressed to the seam of a doorwing, heat blooming at the point of contact as he lapped down its length.

“There are many ways my sea consumes,” Sideswipe purred.

A tingle flared out from Prowl’s back as Sideswipe’s hot vents curled in tendrils, seeping into the sensitive joints beneath his armor.

“You know a Praxian frame well,” Prowl said, unable to stop the charge trembling through his doorwings, even as he held the rest of his frame steady.

“I told you,” Sideswipe said, again at a whisper, “my city and Praxus were lovers once.”

“What happened?” He asked, because he had no idea what else to say as Sideswipe spoke of alliances between cities as being like lovers.

“You’re looking backward, Prowl,” he murmured against him, sending vibrations through his sensors. “But my city?” Dropping the towel, his hands gripped Prowl’s hips, pulling him back against him then turning them toward the balcony as one being. “She’s on the horizon, with your future.”

A charged, loaded silence followed as Prowl stiffened. Sideswipe’s grip tightened, rough, worn fingertips digging into his hips.

“You seek my city’s help for your war.” In the reflection of the windows, Sideswipe’s optics had darkened completely to match the rusted-stain edge of the hurricane lurking along the sea.

Static clogged Prowl’s throat, his fuel pump pounded so hard, he could hear the rushing in his audials.

“Too forward?” Sideswipe asked, tilting his helm, a soft brush of his lips against Prowl’s dataports along his neck in apology.

Prowl awkwardly cleared his vocalizer. “I had planned on opening those negotiations more… delicately.”

Sideswipe’s lips trailed upward, grazing the curve of Prowl’s lower audial ring. “What’s delicate about war?”

“The negotiations,” Prowl said. “We are at a tipping point. A single ripple could set off —”

“No,” Sideswipe interrupted, a dangerous, eager light in his optics. “War is wind and flashes and fire and rust and ruin. You want us as your frontline buffer for Praxus because we have always endured what others cannot.”

“Praxus is not yet involved,” Prowl said, unnerved by how much Sideswipe had pieced together about Prowl’s motivations, and not insulting his intelligence by denying it. “I will do whatever I must to keep it that way.”

“Is that so?” Sideswipe asked. “Look at you, a bold little zephyr. Already speaking for Praxus as if that is your right.”

“To keep Praxus out of it.”

“So why would you think I want my city involved?”

“There is little risk to you,” Prowl said, breaking into some of the talking points he’d prepared. “You maintain a natural, impassible boundary between Vos and Praxus, the heat and magnetic fluctuations make it difficult for fliers to gain lift and navigate, and you have a shield capable of protecting you from the storms —”

“You’re wrong.” Prowl’s spark sank as Sideswipe’s engine rumbled in a deep, vibrating timbre. “We do not cower from the magnetic currents that stir our sea. We hide behind no shield.”

The wind crackled Sideswipe’s next words into Prowl, snapping with the magnetic static of the towering tornados tearing each other apart along the horizon.

“We are the storm.”

Chapter Text

Prowl hunched over his desk, one fist clenched, as he reloaded the satellite weather data. The current conditions overlayed the twelve hour forecast: wind speeds, temperature, pressure vectors, visibility projections — all sweeping across his screens in a dizzying spiral.

Until the predictions themselves became a storm of variables battering the defenses of his neural net.

Tens of thousands of them.

Localized pockets of chaos. Of destruction. Tornadoes and rust storms, forming and dispersing like fleeting static-laced magnetic nightmares. That was before he even accounted for the six unrelenting boundary hurricanes, and at their centre…

There she was.

Sideswipe’s city. The Hexagon. It had to be her. It had to be there.

The city that ate the sky.

It was the only storm Sideswipe could have possibly meant. The how of it, still defied every axiom of logic Prowl clung to, but he could sense the truth of it.

We are the storm.

His battle computer agreed. Relaxed. Retreated to an operating background hum as if to reward Prowl for his conclusion. As if it had always known the should pieces fit into this shape, but didn’t have enough of them to prove it.

It wasn’t proven though, Prowl just had Sideswipe’s word.

And Sideswipe had refused to answer further questions until they shared a drink together — then he had walked out of Prowl’s berthroom, and started drinking straight from the very expensive bottle.

Prowl glanced up from his desk, his questions churning inside him, and he glared at Sideswipe.

A joke. This was all a meticulously orchestrated joke at his expense.

The thought rose within him, a paranoia born of Prowl’s experience with the enforcers who enjoyed watching Prowl become caged in a logic loop when fed false data before he had learned to sort through it.

It really didn’t help that Sideswipe simply lounged on Prowl’s couch, still damp, radiating a smug nonchalance. As if he hadn’t just claimed his city was the terrifying, impassible ever-storm itself at Cybertron’s north pole. No shield. Exposed to the deadly hazards of the sea.

With no thought to how crazy that sounded.

Sideswipe stared back at him, his hand sliding up the side of the bottle in a slow, suggestive caress. Unblinking, never straying, as he drank in Prowl’s mounting frustration as the shock of Sideswipe’s declaration wore off.

“Clever draft that sulks through cracks,” he tsked in disapproval, his pet name for Prowl coming out in a long, harmonic hum of his native tongue. “Little seeking tendril…” he switched back to formal Praxian. “My zephyr, Prowl, join me.” His caress of the bottle turned into an idle trace of his fingers along the neck. “The answers to your mystery aren’t on your glowing screens... or are you no longer interested in re-igniting relations between our cities?”

Prowl inhaled a deep vent, his grip on his desk tightening until his knuckles creaked. It was so tempting to give into the impulse to flip it — shattering the very order he clung to — and the spell of fascination Sideswipe cast on him. The underlying vibrations in Sideswipe’s purred invitation shot through him.

He shouldn’t do what Sideswipe wanted.

After Sideswipe had so thoroughly unraveled him, Prowl needed to regain his control. Prowl had managed to clarify some information from the myth surrounding him and his sea, but in the process, Sideswipe had managed to wear away at him.

An erosion, stripping Prowl’s authority away in thin layers, until he had been left reacting instead of directing.

But Primus, the mech looked impossibly good, sprawled in such a seductive invitation on Prowl’s couch. It was abundantly clear Sideswipe was interested in physically formalizing an alliance between them, and that was a harness Prowl could use. Risky. That sort of entanglement as the foundation for diplomacy could backfire spectacularly in an explosive fall out. And not the way Prowl had been planning to ensure the city of the Rust Sea would keep requesting to deal through him — and him alone.

It was one way to hold a leash on their power, however, and the strategy appealed to his battle computer. It projected a higher success rate than any other path.

Seduction though, wasn’t exactly one of Prowl’s strengths. Prowl’s battle computer seemed to think Sideswipe was willing to do all the work on that front, and he’d just have to go along for the ride. Find opportunities to sink his hooks deeper.

“Why now?” Prowl asked, not yet moving any closer to that temptation.

“Because you went out of your way to sacrifice an excellent vintage to impress me,” Sideswipe wiggled the bottle by its neck between his finger tips. “And it’s a crime I’m left enjoying it alone.”

Prowl sighed, the heavy sound edged with every ounce of his frustration. That path was too risky, he tried to assert to his battle computer. It resisted, refusing to recalculate the risk assessment with Prowl’s added projections of potential, explosive emotional fall out. He rubbed at his chevron and tried not to lean too obviously on his desk to let his exhaustion show. Engaging with Sideswipe was like being tossed into the sea. He didn’t know if he was going up, or down, or about to be ripped apart.

“I meant, why reveal yourself now?” He forced the question out, crossing the room.

He aimed for a chair, because the solution of taking a seat socially to hide his exhaustion was a welcome one. And he wanted to put off making the decision on if he should pursue his battle computer’s top suggestion, for once wishing it would simply crash and reboot.

“Reveal myself?” Sideswipe laughed, sitting up and stretching a leg over the back of the couch. He gestured with the bottle down his frame. “I’ve been nothing but modest in deference to your delicate Praxian sensibilities.”

“Delicate Praxian sensibilities?” Prowl muttered, his course diverting mid-step, a prompt from his battle computer his body obeyed before his mind caught up. “You’ve clearly never been on a fender-bender with Smokescreen.”

He sank into the space Sideswipe had opened on the couch.

“You’re deliberately misunderstanding me,” Prowl said, shifting his doorwings out of the way — then jerked upright the moment be felt them grazing Sideswipe’s thigh.

He glared at Sideswipe, who winked at him.

“You keep leaving me openings,” Sideswipe teased, utterly unapologetic. “It’s in my nature to exploit them.”

It was clear he had done something to mess with Prowl’s doorwings’ sensors in order to move his leg, re-claiming the space along the back of the couch before Prowl got fully settled. It was the only explanation. Because there was no way Prowl wouldn’t have sensed his leg was there.

Unless…

Internally, he scowled at his battle computer’s read-out. He was so tired, maybe its command codes were bleeding into his motor and sensory processes, acting as he had chosen to act on its highest calculated path to success. A solid recharge and reboot should solve it, Prowl decided.

But he was already here on the couch, and it seemed like too much of a mental load to bother to move to the chair — not to mention it would give the clear message to Sideswipe that Prowl was indecisive, and that Sideswipe could keep getting away with crowding his space — so he stayed.

“You’ve made it very clear you wouldn’t be here if you didn’t want to be,” Prowl said, more careful with his words. “It’s obvious you could have left before the shields went up, maintained your anonymity within the Rust Sea, so why did you stay, all but announcing your hidden presence to me?”

Why had he just hung out in the tiny brig room for weeks, waiting for Prowl to come get him?

Because they were all confined now. In here. With him.

“Beyond enjoying the change of scenery?” Sideswipe purred, giving Prowl a long, predatory look.

As Prowl responded with only strengthening his glare, Sideswipe picked up one of the crystal tumblers, filling it way too high, the rare vintage spilling over the rim, then passed it to Prowl.

A deliberate waste; a pure wanton display of power.

In that one act, Sideswipe made it clear he knew exactly what the subtext of this ceremony had been, and he was mocking Prowl for even thinking to try it with him.

The corners of Prowl’s mouth tightened, fighting the urge to snarl. “You know what I mean.”

“The path the wind takes…” Sideswipe slipped into his native tongue, “is never direct when shaping a future landscape.”

The sudden switch was accompanied with a rattling bass-note, forcing Prowl’s spark to skip a rotation. His hand pressed over his spark. He rode the brief, deep thrum inside his chamber out. Carefully, controlling his features, as he took the crystal tumbler from Sideswipe’s hand. The rare vintage stoshed over Prowl’s fingers as he tilted his helm toward Sideswipe and raised his drink in deference, a silent gesture of ‘message and warning received,’ on his face.

Then he set to sipping the fuel to a more reasonable level as more of it splashed on his thighs.

Sideswipe waited, enjoying how Prowl was trying his hardest not to make a mess, before he switched back to speaking in formal Praxian.

“We’ve had a lot of flight-framed Vosians foolishly crossing into our storms of late,” he said, rewarding Prowl’s act of deference with an actual answer, for once. “We’ve wondered what’s been driving them. And I was curious to discover not one, but two Praxians in my sea, beheading their corpses. Is it a common practice in Praxus to claim the trophies of others’ kills now?”

After what Prowl had begun to learn about Sideswipe and his strange, powerful technology, the implication was no longer a surprise. Still, it was nice to have the confirmation.

“So you did kill them?”

“Why do what the wind will give for free?” Sideswipe shrugged, bringing the bottle back to his lips. The overlapping armor plates along his neck bobbed as he took a long drink, then licked at the corners of mouth. “Sunny killed the few survivors. Wanted fresh parts for his garden.”

Garden. The word snagged in Prowl’s neural net, the domesticity of it curdling into the obscene when given the context. He managed to control his reaction from showing — avoided choking on the fuel held at his lips — despite Sideswipe’s sudden, casual admission to the slaughter of seekers for parts.

For a garden.

Sideswipe glanced out the window, his expression going distant again, an ominous foreboding in his tone. “He grows annoyed I haven’t returned with them yet.”

Processing the new information, and determined to remain in control of himself, Prowl followed Sideswipe’s gaze.

“How can you tell he’s annoyed?” he asked.

The storms over the sea didn’t appear any worse than usual.

“Take your pick,” Sideswipe said, a casual shrug to his shoulders. “The dry thunderclap over the scorched dunes, the sharp beam of light through the thunderheads, or the biggest tornados fleeing as far as they can stretch in fear of him.”

He narrowed his optics, clenched his jaw, then took another swig from the bottle.

Prowl took a more modest swallow from his tumbler, already feeling the effects of the extra strong charge on his exhausted systems.

“You can tell all that from the landscape?” he asked, the bubbles popping down his intake, their fumes releasing back up through his nasal passage.

“No,” Sideswipe grinned around the lip of the bottle, his optics glimmering in mirth, entirely present with Prowl again. “He’s my brother. I can always feel his building storms of discontent.” He tapped the bottom of the bottle over his spark. “It’s a roaring symphony of hollow, rusted-stale rage, playing only for me.”

“Your brother?” Prowl sat up, doorwings raising high then fanned wide.

Sideswipe traced their movement as he lowered the bottle from his lips, his smile widening. “That pleases you to hear, my zephyr?”

Heat crawled up the back of Prowl’s neck.“I was beginning to… worry I might be intruding on bonded territory.”

Sideswipe laughed, a low, rumbling sound that vibrated through the couch, through Prowl’s frame. Into his spark. He slipped closer, invading the last feeble bulwark of Prowl’s personal space.

“The borders of our bonded territory are as my city’s are: ever shifting,” he said in a hushed tone, like they were conspiring together outside of his brother’s hearing. “They may overlap in some areas, but it’s all bluster when it comes to him thinking he can tell me what — and who — to do.”

Bonded? Sideswipe was bonded to his —

The mural flickered on a window of Prowl’s HUD: the tiled mosaic of red and yellow triangles contained within the hexagon, two identical, but distinct shapes — one up, one down — overlapping to join into a mosaic of a single star.

“You’re split-sparks?” Prowl asked, his haunting realization barely a whisper.

The realization was like watching the memory file of the alleged ruststalker for the first time. A cold dread raced through his lines, raising every combat protocol to the edge of activation.

Prowl’d never met any split sparks before.

They were always extinguished before given frames — before they could even be. He’d never looked heavily into it, but he had a download for them in his criminal psych profiles. Unstable. Insular. Temperamental. A detriment to their community. Unpredictable. A danger to those around them.

CONTAIN AND DISPOSE.

His throat ran dry as he stared into Sideswipe’s multi-hued optics, processing the commands from his old enforcer files; the directive scrolling across his HUD display like a death warrant.

Sideswipe, blissfully unaware of what was overlayed on Prowl’s HUD next to him, nodded, the smile on his face filled with warmth.

“Brother. Twin. Spark of my spark. One and the same.” His confirmation, spoken with such casual affection, twisted the directives into a practice that was born of superstition and grotesque.

And Prowl wanted to ask if that’s why they remained hidden in the Rust Sea. If they knew all the other cities’ enforcers had this same directive. Wanted to warn him — a flicker of a desperate spark of concern for Sideswipe…

Or — was it them?

Had the directive survived because of them: an eroded wire through history stretching back to some forgotten catastrophe?

The why of it lost until only the warning on the sign post remained, devoid of context, into tales of a ruststalkers and stormsilngers.

A phantom limb of historical knowledge, aching to connect to the neural network of time with the truth it had once held.

A weapon that flashed like lightning — shattering Vos, the survivors fleeing to the sky. The massacre site outside of Praxus.

The city that ate the sky.

Controlled by split-spark brothers.

How many generations had it been since split-sparks walked through Cybertron’s cities? How many countless millennia had passed since the foundations of this forgotten edict was first forged?

Since before the fall of the Thirteen.

Was the scar they had left on history so deep and poorly healed it persisted as an echo across eons as a misshapen terror? It had been so long since anyone had been in contact with Sideswipe’s city, how did Praxus’ council even know to build a split-spark directive and embed it into every enforcer’s training?

There was a time in which Prowl wouldn’t have questioned it. He would have simply trusted them and obeyed.

But now…

Now his spark was pounding, anxious over what that meant for Sideswipe.

Why was his battle computer making this connection? Pulling these pieces together with such terrifying precision, forcing him to stare at Sideswipe through this abyss his own systems dug beneath him.

Her split speakers. They’ve come to —

To what? Why did that prompt from his battle computer keep cutting off like the rest of a file was missing? Why did he even have a file that referenced them?

It wasn’t from the Archives. It wasn’t from his enforcer directives.

It felt… personal. Deeply, intimately, personal. Like it was a memory that had once belonged to Prowl, but had been cut out then reconnected with crossed wires.

“What’s wrong?” Sideswipe asked, through the chaos of Prowl’s mind, only a fraction of a second had passed between Prowl’s realization and Sideswipe catching the slight, involuntary shift in Prowl’s doorwings.

Or maybe, whatever magnetic control Sideswipe had over the winds, meant he could sense Prowl’s internal distress — reading it straight from the electromagnetic field of his spark.

Paranoid, Prowl slashed the read out on his HUD away, erasing the directives. He took a deep draught from the crystal to steady his nerves. The fuel scorched down his intake, and sat like a rot in his tank: a festering, churning acid.

Say something. Say something.

He was taking too long. In a desperate attempt to project confidence, he asked the first question that reappeared from his battle computer after it was cleared.

“You said your twin… gardens?” He almost choked on the last word, but managed to keep his vocalizer static free.

Out of fresh seeker parts.

The images of the bodies found at the mural massacre site and the recorded memory file flashed through his mind. The way each and every corpse had been dissected and posed in a different horror.

‘A remarkably preserved specimen, all things considered.’

It couldn’t have been Sideswipe’s twin who did it, could it? That would make them ancient, older than even Alpha Trion. The stories had to be about a different set of split-spark twins. Maybe their city in the Rust Sea was the only place split-sparks could find refuge. Because there was no possible way Sideswipe and his brother could be —

“Oh.” Sideswipe blew a hard gust from his vents. “That. It’s more of an ‘art project’ than a garden. Statues and stuff. He’s always hunting for new material that tumbles into our sea. It’s not like we have established trade routes anymore, so he takes what he can get.”

Art project. Statues.

It didn’t seem to bother Sideswipe at all that his brother, Sunny, had slaughtered the surviving seekers.

For an art project.

“… you can keep the heads,” Sideswipe said, and for a moment, Prowl could only stare, spark hammering in disbelief. Sideswipe continued on, clearly confused with Prowl’s new hesitation around him. “He mostly wanted their wings, and I’ve spent so long here, getting to know you,” he walked his fingers down Prowl’s doorwing, each touch leaving an imprint of his illicit heat, “those are lost to the sea by now anyway.”

Prowl knew he should be afraid — and a trickle of nervous charge was still feeding his weapons systems — but not because he’d been flirting with a split-spark.

And not because he was sitting beside a being of incalculable age who casually dismissed his brother’s murders for the sake of ‘art.’

It was because Prowl could still see a way. A terrible, beautiful, specific way he could use them to protect Praxus. To stop the war from escalating. To preserve his city’s neutrality, prevent the destruction of Cybertron in an endless civil war — no matter the cost.

They were the storm, and they were monsters.

In another time and place, Prowl would stop at nothing to lock them up. But now that thought was impractical. War and planetary destruction ran on a different scale of calculus than law enforcement. Than the wheels of justice.

If the Vos of old feared them and their city’s power so much that they took the sky, then Prowl had to slip that leash around their necks.

And Prowl, for all his existential horror about what that prediction meant about him in history’s narrative, felt an undeniable pull that this was the only clear path open before him to take.

If other cities fled from the storms, then he would chart them, harness them, turn their chaos of decay and destruction into a weapon of purpose and precision.

Enamored as Sideswipe was with him, Prowl predicted a high probability he could convince them to fake a safe passageway through the Rust Sea. Slowly over a developed pattern. One that seemed predictable. One that they would used to lure Starscream and his forces into a snare. Let Megatron’s prized diplomatic victory vanish along with their arrogant, brilliant Air Commander through an impossible storm of teeth, claws, and rust.

Who could be blamed for an unpredictable turn of a storm? Who would question deeper than fate, claiming Starscream’s misplaced calculations in his arrogance to cut through the Rust Sea on an attack run to Iacon?

With Vos decapitated, Prowl predicted Megatron would lose.

Bloodless, compared to what he saw Cybertron would become so long as Vos under Starscream’s command remained.

And Praxus would be blameless of it all. Their hands clean. The nexus point in Prowl’s calculations not pushing them past the tipping point. Past the point of no return.

Prowl’s city would be safe.

Cybertron would eventually heal, beginning a new age.

He wrapped himself in the solution, its efficiency as cold, elegant, and clean as any other pathway his battle computer could find. If no one with any authority would give Prowl the forces needed to act on preventing his grim predictions of their future, then Prowl would act without their permission.

No permission — but Sideswipe’s. And the grace of his brother, tethered as they were.

“I’ve distracted you from your twin’s request,” Prowl said, regaining a his composure, even as he leaned into Sideswipe’s wandering touch. “In the name of re-establishing relations between our two cities, I insist on replacing what was lost — with interest.”

He swirled the citrine fuel, watching the bubbling liquid lap at the carved crystal — a piece carved from Praxus’ famed gardens, that he could now see standing forever more.

The image of the mural, of the warnings on the sealed door, overlaid with his new, horrific, elegant solution.

Vengeance and chaos will unleash.

The words no longer felt like a curse. Or a warning. Not when he intended to be the one holding the leash.

“How many Vosian wings does your brother want for his garden?” Prowl asked.

Sideswipe’s grin stretched so wide it split his face in an unnatural light, revealing a flash of his sharpened fangs.

“Clever zephyr.” He clinked the rim of the bottle against the lip of Prowl’s crystal, letting the ominous pitch of their negotiations ring out through the air. “Thinking you can ingratiate yourself to me and my city by sucking up to my twin.”

Before Prowl could respond, Sideswipe tossed the expensive bottle of hi-grade over his shoulder, sending it shattering in a violent spray of crystal and fuel against the polished floor. Then, in a dizzying flash, he was on Prowl’s lap — caging Prowl’s thighs between his, pinning them as he pressed their heated panels together.

“Well you can,” Sideswipe purred in alignment with the vibrations in Prowl’s spark. “Go on. Tell me more. Don’t stop.”

Prowl couldn’t stop.

The plan to have the Rust Sea’s split-spark twins of myth and legend rip Vos’ military might from the sky had already consumed him, a deepening decay amid a rush of power that felt like clarity. A way to prevent the coming destruction he foresaw — a vicious preemptive strike.

Prowl now knew there were monsters to be found beyond the boundary line of the Rust Sea.

And no one ever needed to know it was his hand that fed them.

Chapter Text

It was strange how deeply Sideswipe recharged every day.

Wasn’t it?

That’s what Prowl thought as he lay beside him, helm resting in the divot between Sideswipe’s polished shoulder pauldron and his chestplate. They’d fallen into recharge like this again — Sideswipe flat on his back, limbs sprawled and claiming territory as if everything Prowl’s were his. Prowl’s doorwings were given just enough space to not hang off the edge. Sideswipe was like a dense hunk of lead once he fell into recharge.

Immovable.

No howling wind or cracks of thunder through the foothills would wake him — no matter how bright the green dome shield flashed; flashing, as if something outside kept trying to get in. The surveillance systems showed nothing out of the ordinary. Prowl put little stock in it. The danger was already inside with them, and he was the most likely cause. It wasn’t long before Prowl detected a new pattern: the storms picked up every time Sideswipe entered recharge; waves of sand, crashing against the command outpost’s shield.

It was as if the Rust Sea missed Sideswipe, and wanted to drag him home.

To his brother. His twin.

Spark of my spark. One and the same.

A split-spark. He could still hardly believe he was sharing his berth with one regularly.

Those first few times Prowl shared a berth with Sideswipe, every creak of armor or shift of weight from had snapped Prowl online. He had kept expecting Sideswipe to sneak off. Snoop. Try to access Prowl’s command terminal.

Something.

But Sideswipe never rose before Prowl once he entered recharge. He barely stirred. For someone in a new environment, surrounded by heavily-armed strangers while at his most vulnerable, he should have been more restless. Instead, he only ever moved to stroke the edge of one of Prowl’s doorwings.

Skim knuckles across the seam at his waist, beneath his bumper.

A sudden burst of charge trickled through Prowl at the remembered touches and he held back a groan of frustration. Now he really regretted flinging his leg over Sideswipe’s thigh a few hours ago — hoping that might finally wake him, without it seeming like it had been on purpose.

Making him seem desperate.

Not that Sideswipe would mind. Unlike Prowl, Sideswipe was utterly at ease when it came to sharing personal space. And he invaded Prowl’s at every opportunity.

This leg draped over him was as close as Prowl had come to being the one crossing physical barriers between them. He didn’t get any opportunities to initiate. Sideswipe barely gave Prowl time to think before unravelling him: eroding his focus by toying with him from across the room, currents flowing over his doorwings.

Hot, needy lips against his neck; rough, worn fingers slipping beneath his panels again.

Holding Prowl’s desire for him in his palm, as he lapped up the more crude details of their… alliance.

By now, they had interfaced on nearly every surface Prowl had in his quarters. Some, in positions Prowl hadn’t known were possible. He performed his command duties while aching. Between his legs; in his joints —

For Sideswipe.

His battle computer obsessed over each act: cataloguing and replaying them as if searching for a hidden pattern — sinking its claws into his neural net pushing him to repeat another carnal loss of control.

His spark…

Well —

His spark carried the lingering vibration of each encounter with Sideswipe. The very words Sideswipe moaned in his native language still crackled in his circuits, a magnetic charge tugging as a tide beneath his armor, building wave after wave; a quivering pleasure that washed through him and held him under. A claim scrawled across his spark’s crystal chamber — a resonant imprint of his every touch.

And then there was his relentless enthusiasm, the way he exploited every sensitive place on Prowl’s body with his mouth.

Prowl had never had someone desire him so completely before. Had never fallen in with someone so hard and fast.

The weeks passed in a whirlwind.

Being the main focus of Sideswipe’s attention was… intense, to say the least.

The official word was Prowl had given their diplomatic guest his berth instead of having him recharge with his soldiers, and Prowl was recharging in his adjoined private office. To everyone else within the base, Sideswipe remained reclusive, and had declined every invitation Smokescreen kept trying to extend.

He preferred Prowl’s company. And Prowl’s alone.

Very, very, alone.

The excess fuel Prowl kept burning from overload after overload had not gone unnoticed. Smokescreen had questioned the change in Prowl’s rations, concern underlying every word. He kept pressing that they should report Sideswipe and his city to Autobot Command. Prowl refused, insisting negotiations in the Autobots’ favour were delicate and on-going, but proceeding as predicted.

Except they weren’t.

Sideswipe always listened when Prowl talked strategy, but his questions often veered back toward details about Starscream and his trine. He was especially fascinated by the seeker who could allegedly teleport.

Accurate intel was scarce, but Prowl had assured him their plan would account for it. They couldn’t risk Starscream being teleported out from the middle of the snare as the storm walls closed in. Yet, instead of focusing on contingencies, Sideswipe kept fixating on the improbability of the claim: insisting it would take massive quantum computing power beyond the ability of a single seeker in order to teleport. He acted almost personally offended by the claim.

“Vos’ strengths are in photons and illusions, they are bending your perception to trick you into believing this lie,” he would always insist, as if that were an immutable fact. “It’s intimidation. A single seeker cannot teleport: it’s a magic trick.”

And Prowl was no closer to predicting Sideswipe. Or seeing his city of storms.

Sideswipe always dangled the promise of it, and bringing him there to meet his brother, just out of reach. It was starting to feel like Prowl was being left to chase the wind —

A flash of green light split through Prowl’s sleeping quarters, arcs of charge cracking along the domed shield from beyond the balcony doors.

Outside, the most recent storm howled, debris flicking in a heavy horizontal downpour against the electroshield. Mid-day, though the tailwinds of another ruststorm had turned the world a sickly grey-brown. Visibility was near zero. Sand whipped through the air beyond the shield while Prowl continued to sort debriefs from each of his outposts along the Rust Sea’s shores.

If the forecast stayed true, there would be no patrols for the next few days.

In the corner of his HUD, Prowl ran the satellite 12-hour projection of the storm systems over the sea below them. The increased static, magnetic fluctuations, and winds kept interfering with the signal, delaying live updates. Even so, it showed the Hexagon was lazily listing toward the uncharted areas that sank into deep slot canyons connecting the Rust Sea to the Acid Wastes.

What was it doing there? What was Sideswipe’s brother doing there?

The flash floods of the Acid Wastes and its battery acid-like geysers made that area no more habitable than the rusted grain shores they spilled into.

Another flash lit up the haze, followed by a clap of thunder. With the Hexagon drifting near the Acid Wastes, one of its boundary hurricanes pressed against the Rust Sea’s boundary line along the outpost network through the Manganese Mountains. The edge of the hurricane was close: only a few seconds passing between a flash of lightning and its booming thunder.

Another flash.

No thunder.

Before Prowl could think beyond the improbability of that, Sideswipe stirred.

He arched, storm coloured optics dim and distant, blinking at the ceiling. One arm stretched up. Its twin twitched beneath Prowl’s helm where he had it trapped, unable to follow.

Then that roguish, spark-stopping grin formed before he even fully turned to press a kiss Prowl to the centre of Prowl’s chevron.

“You’re still here,” Sideswipe’s pitch rose with each word, his optics no longer darkened as a rusted storm over his sea but blue-green, inviting, and very — very — pleased.

“It’s my day off,” Prowl said, though the words felt insufficient to explain why he’d remained here.

Not since Prowl had been recovering from having his tactical network installed had he laid in a berth this long. He didn’t understand how Sideswipe could do it every day. Didn’t his thoughts or responsibilities begin to consume him?

“My lucky cycle,” Sideswipe hummed, pulling Prowl tighter against the hard wall of his bulk — making it very clear he was already hot and tight behind his panel as he pointedly shifted beneath Prowl’s draped leg. “Oh no, I’m trapped, captured, your helpless prisoner…”

Sideswipe’s teasing skimmed over the surface of Prowl’s spark in a warm front that dropped quickly beneath his panels. So effortless. So easy it was to be swept up and distracted by him.

But not today.

“I want to see your city,” Prowl said, being direct. “I’m beginning to grow concerned it doesn’t exist.”

Sideswipe rolled toward him, reclaiming his arm from beneath Prowl’s head and propping himself on his forearm. His other hand slipped beneath Prowl’s bumper, tracing the seam there, his touch leaving a tingle of static in its wake.

“So you agree?”

Prowl frowned despite the thrill racing though him at Sideswipe’s skillful touch.

He kept asking Sideswipe to bring him to his city. To help him understand it and its power so Prowl could formulate a detailed plan. Contingencies. Allow their… negotiations to continue there. Introduce him to his brother. Formalize this unwritten treaty between them in some way.

Set the stage to officially enact Prowl’s plan. To save Praxus’ neutrality, and with it, Cybertron.

Except, Sideswipe kept insisting on one terrifying condition.

“You know spark merging for me is ill advised,” Prowl said. “I’ve told you this.”

A magnetic breeze stroked along Prowl’s doorwings as Sideswipe lifted Prowl’s hand, pressing to his lips. Charge flooded along Prowl’s arm as Sideswipe looked deep into Prowl’s optics before guiding it down to his chest. His spark pulsed warm beneath their overlapping palms.

“To know my city is the know me first,” he said, his touch wandering, leaning in —

And this was normally where Sideswipe managed to drive Prowl to distraction, but today Prowl dodged his kiss, tilting his helm to the side, displaying his hardline ports along his neck.

“If not in person, then a data transfer,” Prowl said. “Share some memory files with me.”

Sideswipe shook his head, his smile growing tight and strained. “Then you would simply see my city, but not know her.”

Prowl hesitated. He had genuinely thought that was a good compromise. He’d never spark merged before. As attracted as he was to Sideswipe and the promise of this alliance — and as Smokescreen was pointing out with increasing, annoying frequency — Prowl barely knew this mech. But that’s what Sideswipe kept claiming they could solve in this way. A racetrack to knowing him — at reckless speeds that would likely leave Prowl wrecked.

“I…”

Prowl frowned, glaring at Sideswipe. He hated hesitating, and he hated they way Sideswipe kept making him do it.

“I am an excellent guide,” Sideswipe’s whispers filled the opening left by Prowl’s hesitation. His mouth covered the exposed hardline ports on offer along Prowl’s neck — nipping, tonguing, sucking… “Skilled in the matters of sparks. I’ll keep you safe.”

“Safe?” Prowl echoed, jaw clenching, determined to hold the line and not show any evidence of how much he wanted to give in and try again later. “You cannot guarantee —”

“It can be a lot,” Sideswipe said, cutting him off. “For a single spark to know me, and my city.” His grin pressed against Prowl’s neck, a magnetic melody tugging along with his words. “Even with my protection, you’ll likely need to reboot from the overload.”

“I’m certain you are well practiced,” Prowl said, forcing his irritation into his tone to mask his frame’s increasingly loud response to Sideswipe’s relentless attack. “But that’s doesn’t remove the complication. The advanced tactician hardware, and logistical software I am installed with is not to be toyed with — it has driven every other mech installed with it insane.”

“I can handle your little city network in there,” he could feel Sideswipe’s grin spreading ever wider. “Mine’s bigger.”

Infuriating. Primus, everything with this mech turned into innuendo!

“My battle computer is far broader in scope than any city’s internal network.”

“I can handle that too.”

There it was again — that annoying, attractive, unflinching confidence. It practically seized Prowl by the hand, dragging him dangerously close to the line he had been maintaining these past weeks as a clearly defined boundary.

“It’s not about what you can handle,” Prowl said tightly, “but what I can. I am led to believe the experiences one has during a spark merge defies logic. Emotion wrapped in flashes of images combined with physical sensation that does not occur in a linear manner. It will likely overload my system in such a way—”

“Little zephyr,” Sideswipe laughed against him. “The emotional overload’s the whole point of a spark merge — ”

“It could cause a catastrophic crash!”

“I can bring a different envoy to her,” Sideswipe said, raising his head from Prowl’s neck. His optics went distant and he narrowed them, as if peering through the wall. “The other Praxian — not the head surfer, the head stealer — the one that keeps inviting me out — what was his name? Smokeshow?“

“Smokescreen.” Jealousy flashed through Prowl. Its thunderous roar must have crept into his inflection, because Sideswipe pulled him closer and kissed him in the centre of his chevron.

“It’s just… think of it as a security protocol; spark to spark there can be no lies.” His gaze dropped from Prowl’s optics in favour of watching his finger trail the rim of one of Prowl’s headlights. “Without a merge, there can be no introductions to my city, and I won’t be able to give you what you need to save Praxus. To stop the future you see from coming to pass.”

Prowl’s hand trembled slightly against Sideswipe’s chest. So strange to have his predictions be believed unflinchingly. Sideswipe had never questioned it. Why did Sideswipe accept that so readily, but ignore the risk to Prowl’s sanity when it came to a spark merge?

Because he doesn’t see it as a risk.

He was convinced he could keep Prowl's sanity intact.

Beneath his fingertips, Sideswipe’s spark pulsed. He trusted Prowl’s predictions, he was asking for that same unflinching trust in return.

A pact. A guarantee. A show of commitment.

A sign of trust.

Sideswipe acted as a guardian of sorts — a ‘speaker’ for his hidden city in a way Prowl still couldn’t quite translate — and needed more assurances. This was the non-negotiable toll that needed to be paid.

A spark merge.

And risking his sanity.

Well, the infuriating mech was already halfway to extracting that price from him anyway, Prowl thought, his traitorous battle computer feeding him that prompt even as it formed. Prowl swore that thing had developed a bias toward Sideswipe’s favour. It was always pushing him closer to him — as if it liked Sideswipe more than it liked him.

Absurd.

Prowl narrowed his optics at Sideswipe, warnings of ruststalkers and stormsingers overlaying his enforcer directives on split-sparks.

UNSTABLE. INSULAR. TEMPERAMENTAL. UNPREDICTABLE.

ISOLATE.

CONTAIN AND DISPOSE.

Every file Prowl had on split-sparks said they were dangerous. Culled from the population before they caused irreparable harm.

But the way Sideswipe looked at him was so earnest. His touch always so eager.

He spent all day lounging about in Prowl’s private quarters, reading ancient history like it was current events, and desecrating the copies of the Archive’s academic essays on the Rust Sea. Prowl could tell which texts he found the most egregiously offensive by the overwhelming amount of profane doodles he scrawled over the file. Once, Prowl caught him drafting a very threatening letter addressed to the author. He had promised not to send it.

Mostly, Sideswipe seemed to find them amusing.

Sometimes, though, Prowl would find him waiting for him with the fractal etchings from Vos, sharpening the eroded lines of his language for Prowl to study. Technically, Sideswipe had explained, those artifacts were a two-dimensional geometric projection of his six-dimensional language expressed in three dimensional space.

Prowl kept trying to understand it, but he still struggled with the nuances of its foundation.

He could grasp the fourth-dimensional component of it easily enough, sign language, after all, was the movement of three-dimensional shapes unfolding in space and time.

The fifth-dimensional part of it was simple for him. That was how Prowl’s battle computer communicated meaning: clouds of probabilities, all clamoring at once. The noise of thousands of possible outcomes was something he was practiced at sifting into signal to discern meaning.

But the addition of a sixth — that’s where Prowl’s comprehension collapsed.

A language where every impossible shape was a chord — multiple notes and the space between them played at once, resonating with direction, charge, and emotion instead of grammar. It was vibration, oscillating waveforms around the formation of every word to indicate multiple probable states of being at once through place and time. The logic of its repeating patterns, and its nuance, folded and spiraled in on itself faster than Prowl could translate.

Thinking of it again now, his fans ratcheted higher, his battle computer taking more power as static frizzed across his vision.

Soft, needy kisses dragged down his chevron, over the curve of his audial rim. Sideswipe murmured a vibration against him in his language; the static cleared. Charged heat pooled where warm lips touched sensors, sending a stray charge crackling along his jawline.

If Sideswipe had an ulterior motive, if this was all lies — a spark merge would reveal it.

Wouldn’t it?

“Trust me to give you what you need,” Sideswipe’s voice was strained as his lips trailed down Prowl’s throat. “Invite me in, and you’ll see her. Feel her. Know the truth of her — and how much I need you.”

More kisses chased the vibrations of his words. A tongue traced the seams of Prowl’s intake. Sharp fangs nipped along sensitive hardline ports, and Prowl arched with a gasp. Sideswipe’s hands, everywhere — a desperate, needy attempt to convey emotion along with his words —

Was that why Sideswipe was always so intense? Crowding Prowl’s personal space. His native language was steeped in emotional meaning within its syntax, and he struggled to convey his true meaning through formal —

A thumb stroked, then pressed beneath Prowl’s bumper. Sliding in. Flicking the hidden latch only a medic should’ve known how to find.

Prowl sucked in a vent, the sound strangled and cutting off his thought as his plating responded, parting for Sideswipe in a helpless obedience. His spark chamber quaked with a tremor that fractured the boundary he held.

Sideswipe froze, a rigid tension locking the cables in his frame, like he hadn’t expected the latch to actually unlock from his fiddling touch. He stared down at Prowl’s exposed spark chamber, hands quivering, throat bobbing as he swallowed. A fang caught on his lower lip —

Then his optics dilated into a storm as his control snapped.

He was on Prowl in the next instant — a tidal wave of urgent desire. Pouncing. Caging him beneath his braced arms. A frame tense with restraint that shattered as soon as Prowl spread himself wider, and accepted his fate.

Giving his trust, his spark — his sanity — to Sideswipe.

Paying his toll to enter his city.

Worn fingers seized Prowl’s spark chamber, wrenching it open. Burning copper optics drank in the flicker of exposed light.

Then, betraying his savage force, he cradled it. A precious treasure he was honoured to be given to hold.

Prowl vented hard, his spark trembling within the crystal chamber between them, his frame bracing in a cringe as lightning flashed beyond the shield

“Are you frightened of me?” Sideswipe asked, a sudden vulnerability breaking through in his hunched silhouette.

“You’re dangerous,” Prowl answered. No point of lying about that. “But so am I.”

The grin that split Sideswipe’s face caused Prowl’s spark to leap forward in its chamber. Sideswipe’s chestplate shifted open, the light of him spilling out across Prowl.

“That’s why you’re perfect.” He leaned forward, humming a melody full of choked static and desperate longing. “It’ll work if it’s you.”

There was no time to ask what he meant.

Cables ruptured from Sideswipe’s seams, breaching like writhing horrors birthed from deep within the uncharted sea.

They slinked over Prowl’s plating, curved around the narrow of his waist, tracing a path Sideswipe had mapped before they burrowed beneath his spinal strut. Into his seams. The tendrils, engorged with the magnetic charge of current, tunneled through his frame’s narrowest gaps, emerging again at his collarfaring, their warm, pulsating weight slithering over the his neck in an all consuming possessive caress.

“I’ll catch you before you break apart.” Sideswipe panted, his voice fracturing in layers, before his monstrous data cables plunged into Prowl’s exposed ports.

A toll paid and sealed as their sparks collided: a flash of wild electric energy erupting amid eddy currents of a scorching magnetic heat. It ripped a harmonic scream from Prowl — Sideswipe — their identities fracturing, folding, pulled together by the inevitable gravity of fate.

Allied by the parallel hunger of their own dangerous designs.

Their harmony amplified: mind, body, and spark. Sideswipe’s hands drove all over his new terrain, staking his claim. His warm lips and tongue captured whatever they reached as they writhed together. At the same time, Sideswipe surfed through code inside him, skimming lightly across the surface of his battle computer in a soft caress before diving deeper — swimming through every command line, every subroutine.

Prowl arched and shivered against him, choking on Sideswipe’s surge. His power.

Filling. Flooding. Grasping. Drowning. Possessing, and possessed.

The boundary of I blurred into us.

His sense of self split. Diverged. Bled into something larger. Became one — and none.

More.

Far more than Prowl could logically conceptualize.

More than any one mech could contain.

But Sideswipe wasn’t one. He was two. He was born for this life. To navigate turbulent currents. To ride this wave.

This fusion. This invasion. This surrender.

This… symbiosis.

Chapter Text

He was the storm.

Tumbling and curling through pockets of high and low pressure, collapsing only to reform. Falling down, up, and sideways all at once. Jerked through space. Turned inside out through time. Structure, axis, trajectory — degraded.

He swallowed back in on himself. A symmetrical spiral. Orbiting points constantly shifting. Position unknowable until observed.

Everywhere. And nowhere.

Looking in. Looking out. Watching. Being watched.

Being.

A harmony.

Here — inside the storm — inside them — clearly defined, static boundaries blurred into a symphony of probabilities that ran continuously from one to the next. Undefined, until defined through interpretation. Until boundaries were artificially applied to ease a translation into meaning.

Versions of self untangled into waveforms, knotted into glowing translucent ribbons of shifting copper-thread code. Mathematical equations unspooled, represented in a constant transformation of geometry — vertices, angles, sides, curves — pathways flashing when strummed: a multi-dimensional neural net instrument of storm light.

Ground state: that was supposed to be self. One self. Logical. Untethered.

Aligned in response to no other’s magnetic field. No angular momentum. A solitary spin, direction locked in a singular orientation. Fixed. Knowable.

Predictable.

But not here.

He distinguished himself in the torrential chaos of improbability made probable when he felt his flip.

Manipulating the waveforms, Sideswipe inverted the spin in Prowl’s spark into a perfect counter part of his own. Not the rotational axis. At the subatomic level. The spin in every electron. In its magnetic polarity.

Merged on every level, he was aware of what Sideswipe had done as certain as if he had done it himself.

Self.

But no longer singular. He was part of a larger system.

Entangled.

He could feel Sideswipe and his emotions — not just laid bare and accompanying flashes of memory like he expected — but mirrored. Every waveform oscillation inside him found its resonance in Sideswipe… and something else.

A pressure of presence.

Deeper. Ancient. Incomprehensibly vast.

Theirs was a connection beyond chemistry. More intimate than memories shared through a hardline. More intricate than bonding protocols. A symbiotic existence from beyond rationality. Beyond sight. Hearing. Taste. Smell.

Touch.

Sideswipe peeled their sparks open to translate them into counterparts of a sonific symphony: unraveling them into strings of wave functions, collapsing in localized magnetic anomalies with every vent, every hum of their aligned systems.

Bodies. Movement. Direction.

Folding space, time, and points of probability between them down to zero.

Divided.

He didn’t understand the shape of the geometry that held him, only that it had shape.

Simultaneously, he did. A compliment of a shape. A knot. Of all the space in a shape and matter that wasn’t. Pre-determined equations. Paired particles bound by fundamental laws of the universe older than choice.

He felt his tank lurch, and cables thick with charge pulsing beneath his armor while being also the one driving them. He hadn’t agreed to this existence —

Neither, he realized dimly through the mirror, had Sideswipe.

Nor had the other bonded to him through this entanglement. The everything surrounding Sideswipe’s shape that pulsed around him like a silent, overbearing, imprint of his negative space.

A multi-dimensional reflection. Mirrored along a horizon that was ever shifting. One up. One down. A closed system. Independent of any other directional axis. It was their ground state. Their compass point. Their barycentre.

The symmetry, a prison they bore unseen. Knowing no other way of being.

It locked in around Prowl, beautiful, indomitable, and terrible. To be so thoroughly bound since the moment of creation as to have no choice. No consent. No free will on a fundamental level.

Fate.

The nature of their existence — of being them — an unescapable symbiosis that defined the underlying harmony of their reality.

Sideswipe strummed a chord within himself, and it mirrored along the horizon of self.

The melody wove through the translucent ribbons of code, lighting up harmonic strings while dimming others. He wanted rip through the bars. To sever these strings of fate and cut them all free from this entanglement. But he couldn’t find his hands.

Then —

Everything inverted.

They fell.

Up and down through all probabilities of self at once.

And landed. Pede first, their impact sending no shockwave.

In the dunes layered with the full spectrum of oxidized decay. Particles so fine it sifted between metallic equations along the rolling desert sea. The hexagonal storm raging above them stirred no wind in the air. Its rust-red clouds like nebulas birthing stars, pulsing with irregular charge — quantized flashes of lightning quick thoughts.

The storm thrummed an underlying bass note: a deep vibration in a haunting infrasonic B-flat, 57 octaves below middle C. Significantly below the standard range of hearing.

The sand vibrated in cymatic response, sound waves carving perfect forms of symmetry around him.

He looked at his hands —

Were they still his?

His battle computer quivered beneath the pressure of the bass note, blinking subroutines on and off, one by one, like streetlights struggling through a power surge on the verge of blackout.

You’re not alone inside yourself.

He was part of a spin-pair. Entangled with Sideswipe — and through Sideswipe, someone else. And…

Something else.

Impossible to conceptualize in scale. It was more an ominous distortion in the waves. The deep, infrasonic B-flat underlaying the melody of everything Sideswipe did. It belonged to something massive, leaving Prowl with the beginning of an unsettling existential crisis that reminded him he and his predictions were so small — insignificant on the cosmic scale.

There were melodies overlaying the B-flat. Chirping. A twinkling of crystals. Valleys and crests. Ebbs and flow. The poetry of a composition. Pressure and magnetic waves translated into audible frequencies. This noise. This sound. This music. He could hear the vibration of matter. Their harmonics. Electromagnetic waves and oscillations from the turbulence of plasma passing between stars…

The song beneath the storm of the universe itself.

Fuel tank twisting as he stared between the negative space of his fingers at the geometric patterns transforming in and out of the glittering sand, until a shadow passed over him.

Sideswipe, standing in front of him, looking down at him.

Grinning.

His edges were blurred. Undefined. Spinning between states. Impossible to pin down to one phase.

One place.

One truth.

One being.

There was no him anymore. Prowl could no longer perceive him as he once had.

He was tethered to reality through an ancient, infinite symbiosis. Connected to the underlying melody of the universe in a way Prowl didn’t know was possible.

The realization washed over Prowl in a flood of scorching heat: a quantum bond. Not just in spark, but in mind. A state of being that was all at once beautiful, euphoric, and overwhelming to feel.

To be.

But terrifying.

A sense of detachment followed him: the bars of a cage pressed tight around his spark. Sideswipe was used to that weight. It was normal for him. Prowl wasn’t certain if he was even aware he carried it everywhere he went.

Not he.

Them.

In that instant Prowl felt the part of Sideswipe and his twin the enforcer directives warned about. The part of their existence that was capable of watching the universe decay. Hear others burn. Feel them erode to dust by their hands, and they would continue.

Together.

Thinking in the time frame of mountains.

Communicating faster than the speed of light.

Only us.

Prowl’s panic clawed at the seams of Sideswipe’s cage found only within his spark, trying to render the mech he had been cuddled up next to back into one. Reduce him to a tangible, knowable particle, not this… terrifying oscillating wave.

This dangerous frequency.

There was no end to him. Them. A continuous loop.

Were they even mortal?

A warm melody looped gently around Prowl to calm him. Stroke him. A steady, satisfied hum caressed the front of Prowl’s neck, and tilted his chin both within and outside of himself.

And Prowl was forced to stare into the vastness of Sideswipe’s optics. Copper. Aged through eons. Wrapped in a protective oxidized shield. The colour of the ribbons of equations that held his entangled existence between states of being.

In another time and place throughout history, they would be considered divine.

“See?” Sideswipe said, his grin slowly widening and coaxing amid his lyrical pulse closing in around Prowl. “Safe and sound before you broke apart.”

Or recorded as a monster.

As Sideswipe spoke, geometric patterns formed in the sand, small crests and valleys around his pedes. The vibrations of his words, forming shapes that wound in symmetrical fractals wrapping around infinity.

Sideswipe thought Prowl’s existential turmoil and concern for him was funny, in an indulgent kind of way. Prowl could…

Prowl could feel it in the vibrations laced around each word.

He gripped over his chest, disturbed by its unnatural, forced counterpart spin. Fate. An entombed rhythm.

“A solid, familiar three dimensional footing to make you feel more comfortable,” Sideswipe continued, his melody stroking fondly along the side of Prowl’s cheek. “Ease you in.”

Prowl’s battle computer kept drifting his focus to stare at the shifting sand patterns. The sand wasn’t solid. His pedes sunk in slow, symmetrical spirals. His joints locked.

Was he about to crash? Or was stuck here as a symbiotic counterpart until Sideswipe moved?

“Ease me deeper into you, you mean,” Prowl said.

“Into us,” Sideswipe said, a tilt to his helm. “Gently.”

“This… is the gentle version of you?” Prowl asked, translucent ribbons of disbelief wrapping around him. Sideswipe could have at least warned him about the data cables before they erupted out of him.

“Yes and no.”

He’s telling the truth, Prowl could feel it in the stabbing behind his optic as the air vibrated with the emotional shape of the sound of Sideswipe’s words.

Cymatics drawn in light and pulse. Sound taking shape that could be read. Displayed. Felt, as if they were Prowl’s own.

This was Sideswipe’s native language. His native land. His comfort zone.

And he was enjoying Prowl’s unease with it. As fascinated with Prowl as Prowl was with him.

Playing with him these past weeks.

Toying with him. Teasing.

Searching Prowl for something, staring into his optics for a hint of recognition.

Testing how he’d react: waiting to see if he’d remember on his own — wanting him to remember on his own.

Remember what?

The limb he’d left behind. Or was it the other way around? All there was of him was a limb. So small. A fragment of a limb —

“I’m…” Prowl wiped his battle computer’s read out clear. He swallowed — though he didn’t know if he needed to do that here — a grimace on his face. It was starting: his sanity was slipping. “I’m not certain this was a good idea anymore. The data cables bursting out of you in the last second was a little much.”

“But you’re doing great,” Sideswipe’s said, words resonating in cascading patterns, soothing. Earnest.

Sideswipe was excited to have their lives forever entangled. His life and death. He wanted eternity. He could feel Prowl’s emotions in reaction to his, but he didn’t understand why that might be terrifying. Oppressive. Controlling. Overbearing. Sideswipe had never known solitude. He had never once had the background noise of his own spark’s spin unmirrored.

His idea of showing affection and connection was being watched, echoed, needed — always. Invasive. All consuming.

All else felt fake and hollow in comparison to his bond he had always had with his twin.

Primus, this was the gentle version. He would cut a hole in Prowl and eat his internals just to feel him closer inside of him, if he thought Prowl would be okay with it.

The cymatic patterns of Prowl’s horrified realization bloomed in the sand — spiraling like crystal lattices, impossible in their rapid-scale growth. A prison of symmetry that bled at the seams.

The stabbing pressure built in his helm, his battle computer trying to reach out to Sideswipe with a limb that Prowl didn’t have. He could feel it crawling — churning, writhing — beyond himself. As if he’d forgotten that severed part of himself back in Praxus. His fingers twitched, he thought about cutting off his arm to see if it would make the feeling go away.

Clenching his jaw he tore his optics away from the patterns forming behind his optics, blocking them out.

This wasn’t his language.

This terrifying symbiosis was not his existence.

But it was Sideswipe’s. It would always be Sideswipe’s. He resonated the brightest in the chaos to be found within the fundamental building blocks of the universe. He and his twin existed in both a solid state, and in constant flux.

To know it — Prowl had to see it. Experience it. Hear it. Feel it.

Seeing it was making Prowl feel sick and trapped, and knowing it was making him feel sorry for Sideswipe.

His existence felt like a curse. To never feel satisfied outside of his twin, to always want ever closer with others who caught his attention. Until he smothered them. Consumed them. Bending who they were too far until they fractured and broke.

And if Prowl was feeling it, Sideswipe could feel it too. See it written in the patterns across the sand and in the air around Prowl. A tightness formed around them, mirrored a fraction of a moment later on the expression Sideswipe wore. Forming the visual emotion that way as a translation Prowl’s sake.

A non-native language to him he had learned, and still stumbled over from time to time.

He tried to hide the fumbling of his expression from Prowl, his disappointment that Prowl wasn’t instantly enamored with this life, but he couldn’t. Not here.

So, he avoided confronting it through redirection.

“How about some safety guardrails?” Sideswipe said, turning away and making a wide gesture across the expanse of dunes. One by one, black, vertical crystal posts rose from the sands trailing off over crests and depressions into the infinite distance. “There.”

He flicked the one that had risen between him and Prowl. It hummed like a tuning fork.

“If we get separated, you can follow these markers, and I’ll know to search for you along them.”

Prowl jerked, doorwings spiking in alarm. “What do you mean: get separated?”

“If the storms picks up,” Sideswipe said, shading his optics and scanning the endless horizon. “Visibility can get pretty bad. You don’t have a quantum string to guide you through them like I do.”

“What visibility?” Prowl asked, incredulous. “Why are there storms in a spark merge?”

“If my brother feels a strong emotion it’s mirrored in me, and things can get… hazy in here as we overlap,” Sideswipe said, a small shrug to his shoulders, “colliding like waves of high and low pressure until we get it sorted. He’s neutral most of the time so we shouldn’t have to worry about it, but when he’s set off it can get a little intense.”

It feel like Sideswipe was underselling the danger — and he could feel that awareness from Prowl — he turned back, the patterns around him shifting to the crystal lattice of a diamond.

“Do not leave a marker unless you can already see the next,” he said, his expression unyielding in its sudden hardness. “You can’t trust your footprints to tell you where you’ve been. The direction of the wind. Or the sky to remember where you’re going.”

“You can leave me during a spark merge?”

“I don’t get days off,” Sideswipe said, the hardness of the pattern staying a beat longer, hurt that Prowl wasn’t instantly excited to be forever bound together by a fate. “Unlike you, Commander.”

“Days off from what?” Prowl asked, glancing around, optics narrowing along the dunes. “You recharge half the day and lounge around in my —”

But as he went to scowl back at Sideswipe, Sideswipe had already stormed across the dune, beyond the next marker.

And Prowl ran after him, afraid of being left behind in a world where the laws of reality, and free will as he knew it, no longer applied.

By the time Prowl caught up to Sideswipe — three maddening dunes over and already cresting a fourth — the joints in his legs were burning. Every step up an incline sank ankle-deep in the loose sand, the slope sliding beneath him like a tide determined to drag him back to where he started.

Were his knees supposed to be able to ache during a spark merge? He didn’t think so, and he tried his best not to think about it.

Sideswipe, irritatingly, glided over the landscape, unbothered.

“How long until we reach your city?” Prowl called out, reaching the crest of the fourth dune, and almost immediately sliding down the other side into a valley.

“We’re spark merged,” the sand lit up in symmetrical ripples of glowing, transforming shapes as Sideswipe laughed — Prowl’s suffering as Sideswipe flexed his dominance between them improving his previously sour mood immensely. “It’s not a matter of time and distance. Not to my city.”

Prowl sputtered, patterns he refused to acknowledge to his battle computer rippling out beneath him. “Then why are we walking there?”

“So you can know her.”

Gritting his jaw, Prowl internally swore if there was a way to punch Sideswipe in a spark merge, he’d find it. “I thought this was about me trusting you to guide me through this to earn access to indisputable proof of Rusty’s existence.”

There was no hiding his exasperation and frustration, just as there was no hiding from the way Sideswipe was still laughing at him, enjoying it.

“It’s both.”

Frustration frayed around Prowl in sharp, pointed patterns. His mood darkened further as he felt the disconnected phantom part of himself try to move again. This was not a joke. He was risking his sanity for this!

“Are you even interested in helping me protect Praxus?” Prowl snarled, a gust of wind picking up sand and hurling it at the back of Sideswipe’s head. “Or is this all a game to you, and your city of storms only exists between you and your brother’s quantum states?”

Sideswipe turned, his optics a dilated hurricane. The wind picked up around him, lifting sand and blurring his details to shadow. His copper optics burned, twin points of molten metal in a mirage of insulted heat.

“A game?” he hissed, stepping close, circling. “You think I would treat the threat of Cybertron’s destruction, after everything she’s fought and sacrificed for, as a game?”

It took everything in Prowl to stand his ground in the face of Sideswipe’s sudden fury, worried Sideswipe could get offended enough he would leave him here in a blink.

“You cannot know my city as you are: she will consume you,” Sideswipe continued to rage, the sand twisting in a vortex around Prowl, stinging in his seams as it pelted his face. “Your plan is dependent on another more dangerous than Starscream not rising in his place. My plan navigates around all successive unknown variables you cannot yet foresee: I know what Praxus needs for protection better than you.”

The wind pulled back, sucking the sand buffeting against Prowl with it and snapping into a symmetrical, fractal pattern behind Sideswipe. One that Prowl didn’t need to be able to read to know.

The truth. Not a lie. Not even close.

Sideswipe wasn’t aligned with Prowl’s plan. He had his own. Its desert-hot winds blew over Prowl in heatwave of raw emotion, rattling through him in a pressure wave —

One he combined into a greater waveform of his own frustration and need to stop the formation of the future he foresaw, and ricocheted it back.

“Then prove it to me!” Prowl snarled and Sideswipe stumbled back from the blow, his storming optics narrowing at him. But Prowl was incensed, he stomped forward, doorwings rigid, every ounce of command in him bleeding into the geometric patterns around him. “Give me something I can hold onto, and stop dragging me around, wasting mine and Praxus’ time like every —”

The ground rumbled, answering before Prowl could finish.

The low tremor passed beneath them, the pressure wave of something monstrous rising from the deep. The sand shifted. Prowl stumbled back, shielding his optics as the desert burst open — waves of sand spewing in the air. The dunes split as colossal crystal spires erupted forth: at first small, then towering. They bloomed skyward, their formations singing and crackling like frost spreading over glass.

Each grand facet caught in a light source from beneath the sea, and refracted it. Their radiant glow split into kaleidoscopic prisms flickering over Prowl’s black and white painted armor — fracturing Prowl’s own reflection into a dozen of his own faces that surrounded him.

Sideswipe waked among the towering crystal spires as they formed, as they multiplied, and started to thrum with the underlying resonance of that low B flat. Then it was overlayed with new frequencies. Every crystal’s song distinct as if a carefully crafted, unique signature.

As Sideswipe moved through the forest of rising crystals, Prowl kept losing track of him. He’d walk behind a blossoming crystal only to emerge from behind another across the grove, his storm-worn armor now radiant and pristine. His audial horns crackled in a crown of static. A ripple of himself practically teleporting around Prowl through the shining maze.

The final crystal snapped into place and Prowl stared, speechless, at his own reflection spiraling out into infinity.

“Satisfied?”

Prowl jumped as Sideswipe materialized from the space between Prowl’s shadows, his reflection joining Prowl’s into the vast, unknowable endlessness.

With a trembling hand, Prowl reached out, brushing his fingers over the facet they faced. The surface of the prismatic kyanite crystal was warm, vibrating with captured sound as if it were waiting for the accompanying shape of the right frequency from him to unlock it.

“You’ve been to the Crystal Gardens,” Prowl said quietly, trying and failing to not share how astonished he was with every precise detail of the Grove of Reflection replicated around them.

Sideswipe stepped away from him, his reflection swallowed by darkness as he slipped beyond the grove: shoulders hunched, and no longer looking at Prowl as he said, “My city holds its mirror.”

Then he transformed and drove away, travelled through the garden along its twisting, glimmering, sapphire bricked pathways as if he’d traveled the roads as often as Prowl.

Or more often.

He was always out of reach, engine roaring, too far away for Prowl to catch up even in his transformed state.

Until Prowl found him, standing at the base of a large dark crystal. The place in Praxus’ Crystal Gardens that was rarely visited. A place where the crystals remained dark. Never hummed. Never glowed.

The Dead Grove.

A shift in Cybertron’s surface, a quake, was theorized to have cut their lattice off from the rest of the forest. There were jagged lines of frozen charged carved through their centre.

Fractal burns.

A fossil of captured energy that was said to have burst out of Cybertron’s core.

The burns within the crystal were glowing under Sideswipe’s hand. As Prowl approached, they went dim. The illuminant radiance inside the crystal snuffed out, until only Sideswipe and Prowl’s single reflections in the dark, dead facet remained.

“How old do you think your gardens are?” Sideswipe asked, a wave of nostalgia, reverence, and yearning warping every word.

“They are what remains of an ancient crystal clusters forest. Old growth, dating back to Cybertron’s formation. Praxus was built around —”

“Is that what they say these cycles?” A sorrow touched his smile in his reflection.

Prowl frowned, stepping up next to him and half expecting Sideswipe to twist away and vanish. When he didn’t, Prowl visually carved the length of the fossilized energy burn through the centre of the dark crystal, trying to see what Sideswipe was seeing.

A flicker of the crystal mural on the cave door superimposed over it. The yellow mech, riding on an arc of lightning, striking a crystal made of black obsidian fragments.

“You… think that’s wrong,” Prowl said.

“I know it is,” Sideswipe pulsed with a certainty. His voice dropped to a whisper that felt afraid his next words shape would give the wind. “The crystal gardens were a gift.”

“From who?” Prowl matched Sideswipe’s hushed tone.

“Stormsinger.”

“A stormsinger?” Prowl said, disbelieving and annoyed as he crossed his arms beneath his bumper. “The crypid of legend? The one who walks in the storms and sings in the fractal resonance of crystals? The guardian of the Rust Sea who sings the pathway for the lost? That stormsinger?”

“Yeah,” Sideswipe said. “She sang them into existence for Praxus during the formation of Cybertron.”

She?

She.

Prowl frowned as he processed the new pieces of myth snapping into place, then scowled at Sideswipe, his words a resonant seething, embarrassed hiss, “You said your city was called Rusty.”

Sideswipe had had Prowl calling the powerful, hidden city rediscovered in the Rust Sea: ‘Rusty’.

“Affectionately,” Sideswipe tilted his helm, a dry smile curling the corner of his mouth. “And it annoys Sunny, my favourite pastime.”

Prowl’s scowl deepened. “Your brother’s not named ‘Sunny,’ is he?”

“He’ll kill you if he hears you call him anything, especially that,” Sideswipe refused to look at Prowl still, his finger tracing a fork of fossilized lightning. “Regardless of what you may mean to me.”

Curse the fragging spark merge but Prowl could not hide how that quiet confession lit him up inside. And Sideswipe’s true smile returned.

One that mirrored on Prowl’s face, as he was grateful Sideswipe left it at that infuriating knowing. That he hadn’t pushed into the heated shape of the emotions he’d felt from Prowl in return.

“Where is she, Sideswipe?” Prowl asked, forming his name along with the emotions he felt, testing its power. He could feel it: the resonance of a name — a true name — held layered meanings of power in Sideswipe’s language. “How can a city be a storm?”

“By being mobile,” Sideswipe said, waving it away like it was obvious. “She’s is constantly shifting between quantum states.”

“Quantum.” Prowl echoed, already feeling the headache he was certain this conversation was about to cause. “She shifts between reality… and what?”

“The dimensional rift,” Sideswipe answered, and when he received a dull, monotone from Prowl in return, he explained further without explaining anything at all. “You know, the one that was opened in the sky during the Quintesson-Titan war.”

Sideswipe stared at him, waiting for Prowl to have some kind of epiphany. Prowl just blinked at him.

“You don’t know,” he said, confusion radiating from him.

“I don’t know.”

“I figured, maybe… after knowing her name… ” Disappointment rose around Sideswipe and his focus returned to the dead crystal. “The rift was opened to swallow Cybertron. The Titans tried, but even with Kaon pulling from the south and Iaconus pushing from the north, a little sliver of Cybertron is still stuck in it. The Titan’s council could never get it to close.”

“Your city’s trapped in the rift.”

“My city holds the rift,” Sideswipe corrected. “Without her on the frontlines, the rust will spread, the Quints burst through, and all of Cybertron will be consumed.”

“Your city,” Prowl repeated slowly, hoping he was not about to catastrophically crash. “She holds a quantum rift above the Rust Sea? Holds it? With what? Hands?”

“She’s a massive quantum computing sixth-dimensional consciousness who is only theoretically aware of her size she inhabits physically in our third-dimension — all the city-Titans are,” Sideswipe said, as sure as it was written in history as fact. “She’s never seen the need for hands — not when she has mine and Sunny’s to rove all over Praxus for her,” Sideswipe’s reflection winked at him. “But don’t get me wrong, the strain is hard on her,” Sideswipe continued, unapologetic about marching Prowl through the dunes and the aches it had caused him. “Staying in one place hurts her legs.”

Static flashed white across Prowl’s vision, and Sideswipe’s finger trailed down the crystal, drifting over the reflection of Prowl and his chevron — the pain in Prowl’s head released. His vision stabilized.

Had… Sideswipe just calmed his battle computer from crashing?

Prowl stared stunned at Sideswipe. He could feel the truth of the legend Sideswipe wove around them. Even still, he struggled to process the absurdity of it all. The magnitude.

“It hurts her legs… her legs that walk on tornados?” he could hardly believe he formed those words out of myth.

That definitely could not be a part of the myths that were more than metaphor. Right?

“It’s more that we use the tornados to ease the pressure whenever her legs break through from the edge of the rift,” Sideswipe explained as if the matter of a city-Titan breaking through a hole ripped in reality on the north pole of their planet was just another day to him. “Like cushions, to help her rest.”

Prowl didn’t know what to say, it was all so much to process: so much Prowl had taken for granted as fact was wrong. And had Sideswipe just calmed his battle computer?

“Turns out,” Sideswipe continued when Prowl didn’t respond, “When you’re constantly punching through the fifth dimension from the sixth, you exit through the fourth. Time gets involved, and long story short: now she has a lot more legs. It’s just more of her to love.”

— but only succeeded in exposing Prowl to even more fresh cosmic horrors.

“You expect me to believe this?” But that was a reflex. A desperate bid to preserve reality as he had known it. To the time before he knew Cybertron had a dimensional rift still open above its northern most pole. And it moved around, writhing, locked in eternal combat with a Titan. A massive quantum-computing city who couldn’t see where she was walking.

Sideswipe only shrugged, like it was only a matter of time before Prowl would have to believe him. “Do you know why this crystal grove in Praxus is dark?”

“There are theories — ” Prowl started, then cut himself off with a defeated sigh. “That I predict you will tell me are wrong.”

“It’s a portal,” Sideswipe said. “Or was.”

Prowl’s battle computer blanked. “A… portal?”

Why was he even still surprised at this point?

“If we can heal relations between our cities, maybe she’ll let me reopen it,” Sideswipe continued, tracing his finger down the jagged, frozen line. “Maybe… I could come visit you sometimes?”

That was the first thing Sideswipe had ever said in here that hadn’t carried an underlying harmony of confidence. Primus, he had always seemed so beyond anything as mortal as age, but now he just seemed — vulnerable. Young. Lonely. Trapped.

In his cage.

“What do you mean, let you?” A protective streak rose in Prowl, ready to tear strips off anyone who could dampen Sideswipe’s spark in this way. “You’ve already been with me for over a month.”

“I can’t go roving to Praxus,” Sideswipe winced, the pain of the old wound in him flaring. “I can’t go anywhere beyond the Rust Sea for long, I’m already pushing the boundaries as it is,” Sideswipe crouched, picking up a dark crystal shard. He rotated it briefly then discarded it over his shoulder. “It would trap Sunny in the rift, and he’d grow… colder. More isolated. Less interested in anyone else but me than he already is. At least now he still leaves occasionally to gather materials for his garden.”

“Then he could come with you,” Prowl said, not understanding why Sideswipe didn’t see this as the obvious solution.

Sideswipe discarded another crystal over his shoulder as he shook his head. “Then we’ll lose Stormsinger, we’ll never find her again, and she’ll become like the rest.”

“The rest?”

“Your cities,” Sideswipe said. “They’ve all lost their voices.”

“Their voices… what exactly are you to your city?” Prowl asked. “What is your duty?”

“Her voice,” Sideswipe held another part of a darkened crystal fragment up to the light, then discarded it. “Her optics. Her audials. Her tether to her citizens. Her city speaker. It’s my calling.”

The mistranslation of guardian in the old legends was this. Misconstrued maybe with Stormsinger guarding Cybertron from the rift, and blended into this… calling.

This calling as a city speaker. It carried its own inescapable weight of entanglement.

“You… don’t have a choice?”

That sounded alarmingly like the traumatic install of Prowl’s battle computer, and the resulting deaths of all his —

Even as he tried not to think about that, Sideswipe felt the alarm in him.

That infuriating, symbiotic knowing.

“You don’t get to choose your calling. When a city chooses a speaker, you answer. If you ignore the call… well —” He turned and rose, a dark crystal fragment in his hand. He blew on it, singing an underlying melody until a soft blue light turned on inside. He handed it to Prowl. “This is one we need to save Praxus. And all of Cybertron. Something for you to hold on to: like you asked.”

Prowl stared down at the crystal. A ribbon of light wove around it in thin, blue-threaded code as it began vibrating its own weak resonance.

“What do I do with —”

He didn’t get to finish. Sideswipe’s lips collided with his, hands wrapping behind Prowl’s helm, fierce and desperate. Prowl’s back hit the dark crystal, the crystal in his hand knocked against it, and the dead crystal flared with heat beneath his doorwings.

“Please,” Sideswipe whispered against his mouth, an urgent, needy melody bleeding out of him. “I can’t do this without you. We can save Praxus. Then she’ll have to see reason —”

“Reason?” Prowl asked between kisses. “I thought —”

Sideswipe silenced him with a firm fingertip against Prowl’s lips. His warm vents curling the wind in shapes, surrounding around them. Binding them. Pulling them closer.

“Stop thinking,” he murmured, in a melody of command. ”With me, you just need to feel.”

Prowl gasped into the kiss, lips parting as Sideswipe pressed in deeper, the essence of what was him curling over him like a tidal break. The world fell inward — fracturing into prismatic light — and the crystal at Prowl’s back cracked open.

They tumbled through.

There was no up, no down. Only motion. Colour. Patterns. Feeling. Twisting. Grasping.

Prowl’s grip tightened around the glowing shard still clutched in his palm — its pulse a rhythm growing stronger with his spark as they folded through memory as entangled beings.

When they landed, the surface was soft. Smooth, warm. Shifting and swaying. As alive as them.

Sideswipe was already on him, straddling his hips with a feverish need before he finished reforming his shape. Hands everywhere — peeling open Prowl’s plating, pressing kisses that flashed through Prowl’s circuits like lightning strikes.

Hot, fleeting — each one building toward a crest in their entangled waveform that Prowl wasn’t sure he could contain.

“Where are we?” Prowl managed to ask, head tilting back as Sideswipe’s mouth traced along his neck’s ports.

Sideswipe’s chestplate shifted open — his spark glowing the colour of the crystal growing brighter in Prowl’s hand. His pelvic panel snapped back in harmony with Prowl’s. “My room.”

“You have a room in a spark merge?” Prowl asked, dazed, searching for the familiar to grasp.

“For your benefit,” Sideswipe replied, lips brushing the underside of Prowl’s jaw. “With how hard you struggled walking over the dunes, there was no way I was fragging you in them. Do you know how uncomfortable fragging each other filled with sand you imagined there would be?”

Prowl started to answer, but Sideswipe kissed him again — hard, possessive, his hands bracketing Prowl’s helm. There was a tremble beneath the timbre of Sideswipe’s words, an emotion beneath the surface of him.

One he was trying to deny to himself. Trying to hide.

It felt… like a farewell.

Prowl’s spark flared in denial, why did Sideswipe think — and then Sideswipe was making it known he still inside him, outside and inside the merge, in every way.

Emotion crashed through him like a wave that didn’t recede, holding him under. Drowning him. Sideswipe’s longing, buried so deep he’d welded armor over it. The hunger for closeness on all levels. The crushing ache of his existence. Of intimacy like this — because no one could reach him in his city of stormy seas. Nothing could come close to — not without entanglement.

Sideswipe needed this, aching to consume every dripping gasp out of Prowl, to inhale his every vent, because this might be the only time.

Prowl’s spark lurched. His hands wrapped around Sideswipe’s forearm, another against his face. “Why do you think —”

“Don’t speak,” Sideswipe pleaded, covering Prowl’s lips with his. “Please. Not now.”

The thrusts were smooth, practiced, then fast — everything inside him burning, attuned perfectly to Prowl’s deepest fantasies and desires. Arcs of charge shot between their sparks. Prowl felt himself stretch open — expand — with how much of Sideswipe was being poured into him. He couldn’t hold it all. Could no longer feel where he ended and Sideswipe began.

He moaned aloud — his spark flaring bright — and the crystal shard he held burst with light, brighter than a flare, casting the whole room in a kelidoscopic resonance.

A new, unique pattern emerged.

He saw the majesty along side the tragedy of it now — how everything Sideswipe was had been sculpted by this intimacy. How shallow and pale any connection felt outside of it. How even Prowl’s own life suddenly felt ordered, clinical, and sterile in comparison. Disconnected, he’d been quietly starving for this without knowing what part of him was missing.

The overload from knowing and being known ripped through Prowl so hard his entire frame shook. A violent rattle in his vents, a tremor in his grasping fingers curling to take in more — hold on to more — and he wasn’t sure if the new song that transmitted through the air was his or Sideswipe’s or both.

One of pain, and longing, and need, and —

A knock rippled through the walls. Soft at first. Three beats, confused and worried.

“Sides?”

Sideswipe went rigid, a guilty fear sprouting in patterns around him.

His hand clapped over Prowl’s mouth as his optics widened.

“Quiet,” he mouthed.

Prowl tried to swallow back the cry tearing through him, tried to stop shaking — but the overload kept pushing through his control. He bit into Sideswipe’s palm as it crested.

The doorknob jiggled. “Sides?” Then again, harder. “Why’d you put up a block? What’s wrong?”

“It’s nothing, Sunny,” Sideswipe called in a false calm. His free hand groped to materialize a blanket, tossing it over Prowl to muffle his vibrations. “Just tying up some loose ends before I —”

“Who’s with you?” The walls warped, bowing inward. “Who did you bring here?”

“No one.”

A lie. A useless, stupid lie in a place such as this.

Everyone knew it. Could feel how it stung from multiple angles at once.

Before Prowl could think to react, Sideswipe grabbed him by the shoulders and shoved.

He fell backward through the berth’s headboard — through the wall itself — and landed with a muffled grunt on a dune of fine, cool, white zinc-oxide sand.

He blinked. The crystal shard in his hand still glowing — faint now. Flickering like it, too, had been suddenly thrown out in the cold. The unique resonance Sideswipe ignited into it for Prowl, threatening to die.

Above him, storm clouds were gathering. They billowed in thick, churning, swirling, masses. The pressure dropped, Prowl’s audials popping to adjust. The temperature plummeting just as fast.

Prowl lay there, confused and stunned. Alone. His frame still quivering with the last tremors of Sideswipe’s fervent passion imprinted in him.

In the distance, the howl of a feral pain unleashed, ripping across the sky in flashes of fury punctuated by deep percussive, thunderous beats.

Panicked, Prowl located the nearest marker Sideswipe had left for him along the dunes and ran.

Footsteps behind him quickly erased into the sea, by a chilling, bitter wind.

Chapter Text

Sand pelted across Prowl’s armor as a raging storm wall descended from the sky: tornados piercing through the clouds as electrified claws and serrated teeth. Visibility closing to near zero fast. Pistons pumping, engine redlining, Prowl dove for refuge at the base of the black crystal marker Sideswipe had left for him along the dunes — just as a towering column of destruction sealed around him.

He collapsed, knees and bumper sinking into the sand, vents heaving, engine heated with a physical strain that shouldn’t be possible here. Sideswipe had made it seem like Prowl was imagining it. On his race to the marker, he kept trying not to imagine it — and that only made his race up the dune’s crest worse. The grit he felt clogging his filters and pistons wasn’t real. The strange, new magnetic pull on his spark — spinning it off its axis, spiraling it toward an ever-shifting field — threatening to rip it apart, was unfortunately very real.

He was still merged with Sideswipe, and Prowl had no idea how to end their merge. Didn’t know how to talk to Sideswipe surfing through his systems. Sideswipe wasn’t releasing his hold on him. Maybe, couldn’t release his hold; his waveforms colliding with his twin’s, and Prowl was trapped here to ride out the storm.

“This is awful,” Prowl said, groaning, still face down. His over-heated systems clicked as they cooled against the white oxidized sands. ”Why does anyone spark merge for fun?”

Because the rush of ‘knowing and being known,’ the worse parts of him still wanted — needed — consumed in and consuming Sideswipe, had been amazing.

Before he’d been tossed out of his ‘room’ as ‘no one.’

“Ugh,” he revved his engine, annoyed with himself and the lingering imprint of Sideswipe’s charge still tingling through his systems. “This was such a bad idea.”

Now, in addition to the periodic phantom limb feeling he’d have to fight, he had this gaping hole inside him, knowing what he had been missing out on all this time just to have it cut away.

Keeping his hand affixed to the base of the marker, Prowl vented beneath another groan as he rolled on to his back. It was awkward, getting his doorwings spread out beneath him while his limbs felt like lead weights, but he managed without having his elbow give out on him. As he sank into the cool sand, circuits, spark and mind buzzing, he blinked upward. A gargantuan column of sand-blasting force filled with sharp, strewn debris surrounded him in this narrow pocket of calm. The memory of the two tornados he’d watched from his office ripping apart a third without pause, simply for being in their path, haunted him. If he stepped out of here, he was certain his spark’s waveforms would be ripped to shreds, scattered, and shared between Sideswipe and his twin.

“‘My brother’s neutral most of the time,’” Prowl muttered in an impression that sounded more like Smokescreen than Sideswipe. “‘It shouldn’t be a problem.’”

Well, it was a problem. Who else could have been knocking at the ‘door’ of Sideswipe’s room in a spark merge if not the very being he was entangled with since creation? And in glaring, obvious hindsight, it was clear Sideswipe knew bringing Prowl here would be a problem with his brother.

A big one.

He’d done it anyway.

As Prowl’s systems recalibrated from the jarring shock of being shoved out of Sideswipe’s room and into the dunes, mid-best-overload-of-his-life, Prowl tilted his helm back. The black crystal marker loomed in the centre of the vortex. His tank bottomed out.

It was beginning to feel like Sideswipe had left Prowl a headstone.

The farewell he’d felt from Sideswipe... what did he know that he’d been avoiding telling Prowl?

In Prowl’s hand the weak struggling hum of the new, unique pattern Sideswipe had created for him filled what should have been a deafening roar in the centre of the tornado.

It was otherwise silent inside the spiraling wall of destruction. It shouldn’t be silent. It shouldn’t be calm. A violent updraft should be ripping Prowl away from the marker — his headstone — the variables of this new reality crashed in on him.

There shouldn’t be a rift torn in the fabric of space on Cybertron’s north pole.

A city shouldn’t walk on tornados.

”She’s a massive quantum-computing sixth-dimensional consciousness who is only theoretically aware of her size… all the city-Titans are.”

All of them?

… Even Praxus?

The familiar, warning stab of pain built behind his left optic, and the increasingly familiar weight of the missing part of him tried to move.

The whirlwind tour through ancient history — that felt like only a few years ago to Sideswipe — raced as new variables inside his neural network, and his battle computer was dragging Prowl careening, overclocked and out of control, into a corner.

He was going to crash.

… Had Sideswipe really calmed it for Prowl earlier? Could Prowl learn to calm it himself?

Useless questions, for all the good they did Prowl now.

Prowl tightened his grip on the ignited crystal shard Sideswipe had said they needed to save Praxus. Forced his arm to move even though it didn’t feel like his anymore. He looked at the glowing crystal fragment Sideswipe had brought to life from a part of the Dead Grove.

”Something for you to hold on to: like you asked.”

It pulsed at him, blue-ribbons of light wrapping around his hand — holding onto him in return. Holding, and being held. Trying to match the frequency in Sideswipe’s language, Prowl pulsed back at it.

It lit up, glowing brighter, the streaks of blue light weaving in and out of the seams of his armor, carried along the lines of his electromagnetic field, entangling into them.

Not wanting anything else foreign installed inside him that he didn’t understand, Prowl switched the crystal to his other hand. He pulled until the translucent ribbons of light were extracted from beneath his armor in sinuous little threads. A few of them tore. Its tattered remnants retracted back on itself. The crystal dimmed, and Prowl had the ridiculous notion he’d just made it sad. He pulsed its unique pattern back to it, only to receive a weak flare of light in response. It appeared to be pouting.

Unnerved, Prowl sat upright, spreading his doorwings and resting them against the marker in the sand. He flipped the glowing crystal shard in his hand, confused how it was meant to save Praxus — a weapon’s energy frequency, maybe. Its unique resonance a blue print. It was enough to distract his battle computer from the crushing weight of the new, painful variables Sideswipe had dumped into him. The pressure from behind Prowl’s optic released, for now. He flexed his hand that the streaks of light had woven through as if trying to install itself, then rubbed over his chest, trying to smooth out his rumpled electromagnetic field lines. It didn’t help. His spark still stung as if it’d been slapped.

“Who’s with you?”

“No one.”

That sting. An elastic band of Sideswipe’s lie, snapping within Prowl’s spark.

No one.

Was the lie meant for the one knocking on Sideswipe’s door? Or was Prowl no one to Sideswipe?

That didn’t seem right, and he discounted it as soon as he considered it. He had felt exactly how Sideswipe felt about him in the Dark Grove of the Crystal Gardens’ mirror, but Prowl was completely out of his depths here. He wasn’t practiced enough with ‘matters of the spark.’

Not like Sideswipe was.

Without him here, weaving Prowl into an electromagnetic eddy that was barely managing to hold on to Sideswipe’s turbulent wake, the inconsistencies Sideswipe displayed were becoming more obvious. He knew he couldn’t lie to Prowl merged as they were — but he had been navigating Prowl away from realizing something.

Why had his kisses carried forward a tormented grief of a loss not yet lived. His touch so urgent and frantic —

A farewell.

Why was he so convinced they were doomed when they were only getting started?

Prowl could feel Sideswipe still. Muted. His vibrant presence akin to trying to make out the harmony in a song that was muffled by walls across a street. Sound dampened. He was feeling… nervous? Guilty even. Really scared.

Or were those Prowl’s own suppressed emotions mirrored back at him: leaking out and rotting in his chamber?

It was impossible to be certain where Sideswipe ended and he began. Prowl hated that. Hated these blurred boundaries. It was stifling to have no privacy within himself. To leak them like a sieve. To never be certain if what he was feeling were his own motivations, or the influence of another.

The only senses he could be certain were not his, were the presence of the others.

If only Prowl could stop trying to understand Sideswipe and his brother in terms of fluctuating quantum orbits and changing energy states…

He fixated on the disorientation he had felt when Sideswipe had flipped the spin of Prowl’s spark.

Their barycentre, a spin pair —

They were oriented to each other. Their magnetic polarities in their sparks were each other’s magnetic north. No matter where they were in space, or time — dimensional rift — they were aligned. One vibrating in response to the other.

Simplified in classical physics as an orbit. A bright oscillating pulsar eclipsing a bigger, looming gravity well in perfect alignment — Prowl hidden from its view in the path of totality.

Hidden in a shadow at the edge of gravity.

Prowl couldn’t feel the oscillations of Sideswipe’s twin clearly. Sideswipe was in the way: intercepting the waveforms. Did that mean his twin couldn’t feel Prowl in detail, either?

Therefore, since Sideswipe had aligned Prowl’s spark to his… his brother’s was currently the same polarity as Prowl’s. The same spin. Not flipped. Like a magnet, they were both connected on either side of Sideswipe, but their charge repulsed each other.

Is that how it worked?

Theorizing the colder presence Sideswipe blocked was his brother didn’t account for the other. That infrasonic B flat beneath the violent collisions and supernova explosions that crescendoed into a moment of calm: a refrain of a twinkling star field. That music wasn’t coming from between Sideswipe and his twin.

It was coming from the one translating the song beneath the storm of the universe itself, for them to hear.

Suddenly, an immense pressure built in Prowl’s mind: his battle computer engorging like a swollen battery pack about to burst. He pressed the crystal to his chevron, with the ridiculous notion that maybe that would help. The pressure he felt was distorting space. Limiting on the boundary of infinity. Its curve never quite touching any axis.

This one was not blocked by Sideswipe’s spin. Could not be blocked. And it had begun to turn its attention toward Prowl: a being that knew the name of every curl of gentle wind to every tempest gale on the cosmic scale. Who mapped the ever-shifting waveform terrain like the rolling dunes of a desert, down to every grain of sand in its sea of probabilities. The probabilities it calculated, more numerous than the stars in the sky —

Prowl’s presence, no longer drafting in Sideswipe’s wake, had disturbed the background harmony. Knocked some bars of sand out of place in his mad dash. Created a drip. A ripple. One that transmitted outward. One she could feel.

Sideswipe’s city.

Stormsinger.

The Titan from the era of legends who stalked in fluctuating states in and out of reality within the depths of the Rust Sea. The one who had shattered Vos to fragments, and driven it to flee to the sky —

No.

She ate the sky.

With the rift.

And she had driven Vos to seek refuge from her rage, above her symphony of cosmic storms.

Out of her vengeful reach. Because Vos… was also a Titan, fragmented physically but still whole on the quantum scale. Just, voiceless. Without a speaker. They all were.

Kaon. Iaconus. Vos. Helex. Tarn. Kalis. Polyhex. Nyon. Praxus.

Nine of the ten Titans of legend had lost their speakers.

All except for her.

He knew that now, as certain as myth and legend had become historical fact: the context worn and abraded through the sands of time. What remained were fragments, pieces of what she was capable of, drifting in a distorted parallax.

Prowl shied away from her awesome power. Presence. Her emotions. Feeling her turn toward him wasn’t like plugging into Praxus’ city network with his battle computer. It wasn’t information about automated systems or archives. It wasn’t stoplight signals, airduct flow rates, traffic patterns, or fluctuating power grids.

It was all that, and so much more.

A consciousness so massive it distorted meaning itself. It was so far beyond Prowl’s capabilities to comprehend. His tactical network, in comparison, felt like a tiny fraction of her city-Titan network.

A limb — not even a limb — a tiny sliver of a limb carved out of —

Praxus.

He sat stunned, glowing blue crystal in hand, and staring blankly at the single readout of probability displayed by his battle computer. No other option, no matter how minuscule a statistic was given. A single result. A single point of truth. A single reality.

No other.

Praxus.

It flashed again.

Sickly grey symmetrical tendrils rose from the sand, formed of Prowl’s turbulent and mortified emotions that he couldn’t suppress. They clawed at him. Choking him in tormented screams. Tunneling through him.

Installed in him.

His battle computer: the very experimental hardware and algorithmic software surgically entwined into Prowl and his neural net, stared back at him from the void inside his mind. Every subroutine abruptly lit up: screaming an echo of Prowl’s batch-mates’ terror. A fragmentation that had seemed singular, now coalescing into a unified chilling chorus.

Praxus’ screams.

The city-council had carved up pieces of their speakerless city-Titan’s core. Implanted them in carefully curated batches they had commissioned through vector sigma and the All Spark, brought online at full power and function. An entire batch program — forty-eight minus one — a single survivor of the remaining forty-seven. And even Prowl had been considered glitched due to how often he crashed.

That’s what the Tac Net project had been.

The council had been trying to harness a fraction of the quantum-computing power of a Titan.

… The cave on the outskirts of Praxus. The archeological site. The mural. They must have found something else in there. Something that wasn’t in the Archives.

They knew.

And so did Sideswipe.

I can handle your little city network in there… Mine’s bigger.

He had grinned. And he had been calming the fragment of Praxus inside Prowl, because… Praxus knew him.

That first moment they met, that fragment of Praxus’ core, Sideswipe must have recognized the harmonic signature of its function for what it was as it crashed. The way Sideswipe had kept his unblinking gaze on him, as if Prowl was the most fascinating mech he’d ever met. How he came onto him. Laughing at him as if waiting for him to catch up with the joke.

As if waiting to be recognized.

Because Sideswipe was his city’s optics. Her audials. Her voice. Her hands.

Her touch.

The fragment of Praxus in Prowl recognized Sideswipe’s touch. His harmonics. His waveforms.

Dear Primus Almighty.

Prowl stared at the crystal in his hand as he felt his phantom limb try to take the shape of his entire city. He could feel the parallels of how his tactical network operated in probability clouds sifting through the fifth dimension.

He could also feel the stark, terrifying contrast of how it paled in the shadow of Stormsinger’s full calculation capabilities.

The chipped off piece of Praxus within him was integrated into his neural net: an operating system that, like all Cybertronians, was rooted in classical physics. Prowl dealt in the finite and the predictable.

He computed the motion of observable objects, mapping linear patterns and probabilities through linear passages of time. The sheer amount of variables he could process distorted how he perceived large scale events. He saw battlefields and crowds acting as a liquid or gas, in terms of fluid and thermodynamics, searching for anomalies moving against the flow of causality and causing eddies of turbulence instead of individual faces.

Beyond Smokescreen and Datarider, he didn’t know a single one of his soldier’s names. They were clouds of skills he assigned function. Using them as extensions of his will.

As his hands. His audials. His optics —

Prowl’s will ran on statistics, probability, the odds — on choosing the highest realistic result for success on a mass scale over individual survival. He was built for a deterministic reality, operating on a higher computational scale than any other living Cybertronian.

But hers was a mind forged in deep time.

She processed changing quantum states in an endless cycle, a vast parallel computation akin to predicting shifting weather systems, their matter and energy observed at the sub-atomic level. She didn’t perceive reality as solid particles but as wave functions; probability to her was inherently indeterminate until observed.

Vibrations touched. Felt. Heard.

The bots of her city would have never been known to her as individuals; they would have flowed through her crystalline corridors, the spectrum of their lives a liquid, translucent ribbon shifting and drying, eventually, to a trickle. They were perceived as interconnected probability fields rather than discrete entities.

Her quantum mental existence was not linear, how utterly vast her mind.

Now, trapped holding the rift as she was, neither was her physical existence.

Over millions of millennia she had become more like a force of nature. Was more like the winds; everywhere and no where at once, observable only by her effects on a landscape.

On her sea.

She knew of the third dimensional realm containing the planet she safeguarded — that her body had once been whole there traveling along with the linear lives of her citizens — but her mind, her consciousness, had always been quantum. She had only ever connected with the third dimension — physically touched it, tasted it, saw it, heard it, processed it — through her city speakers.

She was sentient, surely, but not in a way Prowl knew, or found relatable. Trying to conceive of her in her unfiltered, unpartitioned-entirety lay madness.

Myth was easier.

Legend more effectively conveyed reality to those who would never know and understand a Titan’s mind.

And Prowl had a fragment of a Titan of legend’s consciousness, just like her, grafted inside of him.

Prowl couldn’t let the abject horror of it fully sink in. Could not afford to allow himself to process it beyond the analytical. But it kept trying to bleed in —

His neural net, his own cortex, dripping, stained and splattered in Praxus’ blood and torn quantum network. His confused, sightless screams as he was hacked apart and fused with minds who could not comprehend even a small fraction of him —

— this was a survival situation.

Prowl needed to shrink away. Break the merge. Get out of here before Stormsinger realized a part of Praxus had been chopped up, cannibalized, and —

The screams of his batch-mates split in harmonics inside him. A superposition of terrified screams from a city that still lived in him. The voiceless, once revered as divine, finally given a way to speak again, only to feel terror. Turned upon by his own citizens, picked apart and dissected alive; treated like carrion.

The obsession with the myths of the city in the Rust Sea…

Praxus knew them.

Had lived them.

Her split speakers. They’ve come to…

Not as myths. Or monsters. But his demi-god heroes.

They were lovers once.

Stormsinger was a city-Titan frontline warrior.

She held the frontlines of the Quintession-Titan war to this day. She had never gotten to settle in peace like the rest of them. For her, maintaining their peace was a battle that still took place on the cosmic scale.

She held the hole torn in the fabric of space that threatened to destroy all the she and her fellow Titans and their speakers had fought for —

Sacrificed for.

Cybertron.

And their right to be free.

She was going to obliterate Prowl the moment she noticed the scars of enslavement he bore of her once lover. He was certain of it.

Her split-speakers, they’ve come to —

Save Praxus from his citizens who had been picking him apart: speakerless, voiceless, trying to force him and his power under their control.

Prowl was lucky Sideswipe hadn’t slit his throat and ripped out his spark the moment he recognized the harmonics of Praxus inside him. Luckly Sideswipe had been curious. Had stayed wondering why Prowl didn’t seem to know him. Didn’t remember their entangled past.

The pressure built around the swollen pain in Prowl’s helm. He pressed the crystal to it harder. He had to get out of this spark merge before the catastrophic crash that was threatening to burn through his mind —

But…

She was why Prowl was here. Why he was risking his sanity. He had wanted to see Sideswipe’s city. Understand it. He had lusted for the power of a Titan.

To protect Praxus.

And the future of Cybertron’s security.

A hope for peace.

Jaw clenching, he stood against the pressure pounding in his head, in the centre of the swirling vortex.

It seemed the right thing to do: greet a legendary city-Titan warrior while standing.

He raised the once dark crystal to his lips and, like Sideswipe had done, blew on it.

Like a fire starved for the attention of oxygen, the glow within it brightened.

“Greetings,” Prowl said, in formal Praxian, far more confident sounding than he felt. “I am Prowl of Praxus. A piece of him has guided me here in want of re-opening relations between you. A dangerous threat looms within Cybertron’s population. Praxus has suffered in absence of a voice, so I speak for him: he calls for your aid.”

The air around the crystal warped in blue-ribboned streaks, rippling in response to his greeting. The light inside it pulsed harder, brighter still —

But Prowl received no other response.

He flipped it end over end. Then shook it a little. It buzzed. Pulsed a confused pattern. But nothing else.

Of course, Prowl cursed himself, resisting the urge to throw it on the sand. Foolish to think Sideswipe would just hand him a commline to his city.

That anything involving Sideswipe would be simple.

He sighed. Straining his neural net for a solution. Sideswipe logic it was then.

What would Sideswipe do?

Sing to it.

Prowl cringed. Mortification distorted around him at the suggestion.

He couldn’t sing. His only attempts at speaking Sideswipe’s language had been lifeless. Tone deaf. He was much better at reading it.

Besides, what melody would activate it? What pitch?

What words?

Hush. Do not speak of her when the wind is high…

The refrain from Sideswipe’s low, haunting dirge echoed faintly from his battle computer’s memory.

From the fragment of Praxus.

The gore-stricken horror of that was actively suppressed from rising, pushed down by Prowl with practical solutions.

Well, Prowl thought, glancing around at the tornado’s walls, the wind was certainly high.

Hush. Or you may draw her vengeful side.

Prowl grimaced as the rest of Sideswipe’s refrain whispered from his memory files. He really wasn’t keen on drawing a warrior city-Titan capable of holding a rift in reality and shattering another city-Titan into fragment’s vengeful side.

But it was the only lead he had. He did as Sideswipe would do: give himself to the flow of chaos, and not over think it.

Prowl raised the crystal again, and whispered her name into it with the best harmonics he could manage in Sideswipe’s native tongue.

Her true name: wrapping the emotions of his awe, reverence, and terror regarding her and her power into every oscillating wave.

“Stormsinger.”

The instant the vibrations left him, the tornado changed. A dark silhouette appeared in its spiral. Moving as if swimming in the storm’s rotation. Something big.

Circling.

Hunting.

An audial piercing shriek, a gravel-laden scream of grinding crystals rising within it.

A song.

One not sung to him, but around him. A sonar searching for his electromagnetic pulse. His vibrational frequency.

The shard of Praxus within him recognized the shadow for what it was, unhelpfully pointing out that if Prowl had run the probability of his chaotic instinct through it first, then Prowl would have realized that Stormsinger’s ‘vengeful side’ in the refrain was not, and had never been, in reference to her.

Cross-referenced with the version of the text scrawled on the sealed cave door outside of Praxus —

A warning.

Do not speak of it when the wind is high. Erase its name from memory. From record. From your lips. It listens. Walks among you.

It will draw near. Vengeance and chaos will unleash.

Devouring all in its path.

It. Had arrived. It walked among them. She did not.

By saying her name, Prowl had called it.

The distorted silhouette in the tornado slowed, shifting its optics alit in a burning molten flame, searching the pocket of calm for the one who had been so foolish enough to speak a name of power and draw it near.

“… Sideswipe?” Prowl asked in a hesitant whisper, part illogical wishful thinking, and part a desperate, nervous call for back up.

It wasn’t wild or playful or bright. It wasn’t warmth pressed against his chest; wasn’t the lingering hum of a kiss on the tail-end of the overload that refused to leave the static in his lines and the magnetic charge in his spark.

It was cold. Calculating. Vengeful.

The promise of extinction itself in a single glare. Prowl knew it.

It was Sideswipe’s brother.

As the silhouette condensed, standing fixed within the swirling mass of the towering column, the name Prowl had for it — for him — died in static in his vocalizer.

”He’ll kill you if he hears you call him anything, especially that. Regardless of what you may mean to me.”

Taking Sideswipe’s warning to spark, Prowl took a wary step back, anxiously flicked his doorwings — they hit against the crystal marker —

It rang like a tuning fork.

The glare of extinction locked in on the vibrations and lunged —

Strong hands seized him by his shoulders, a scream that couldn’t form folded into him as the world flipped.

Reality inverted with a nauseating twist as gravity failed and orientation disintegrated. Prowl’s tank convulsed in a dry heave of corrupted vertigo. A silhouette loomed over him, crushing his helm in an iron grip —

Sideswipe.

It was Sideswipe.

Standing too close after reaching through Prowl and transforming him impossibly inside out before recombining him — instead of simply turning him around.

Sideswipe.

Holding Prowl’s face in both hands, firm enough to still his trembling entirely.

Sideswipe.

His presence pressed close, his name chanting in Prowl like a litany of prayer. Here, spark-to-spark, Sideswipe was suppressing Prowl’s own instinctive flare of panic.

That easy smirk, that effortless confidence was nowhere to be found. What remained was a strained false calm, optics sharp, protective and wild in their dilated, storming depths.

“Be still,” Sideswipe murmured, voice low, like a handler calming a treasured, spooked pet. “He’s just curious who I’ve ensnared in our orbit.”

Prowl flinched at a cold touch on his back. His optics flared at the strange sensation of his spark being unzipped from behind.

“He’s —”

“I know his touch is cold,” Sideswipe said, both thumbs brushing along Prowl’s helm as he hummed a soothing melody. “Just don’t move, don’t scream, and he’ll get bored with you and lose interest.”

The touch of Sideswipe’s twin was more than just cold. It left an antiseptic sting in its wake as a sharp claw traced the ragged slit exposed in the back of Prowl’s spark.

Stroke after carving stroke. Slow. Patient. Methodical. Digging in, chiseling, removing the negative space of material defining Prowl beyond Sideswipe’s eclipse, with an expert sculptor’s precision.

Repeating again. And again.

And again.

With each pass, more of Prowl’s spark peeled away.

Left dangling out of him.

Thin curls of himself were being lifted as ribbons — combed through curious fingers. Arranged. Sorted. Braided. The way one would sift strands of spun gold searching for defects.

For material contamination.

The core of Prowl’s self and his emotions hung separated on every ribbon. Fear ignited when wrapped around a fingertip, woven with guilt that tasted bitter and vile. His ego was flicked to the side along with his confidence, minuscule in comparison to the one evaluating him. His humiliation twisted with shame that was stretched and thinned like an energon sweet boiled, reduced, and pulled to thread.

That single sweet string of him — him — was drawn between warming fingertips. Lifted.

Brought to parted lips.

The suction stole the charge from Prowl’s limbs. He sagged into Sideswipe’s hold, against his frame.

“S—Sideswipe —” he gasped, terrified.

“It’s okay,” Sideswipe soothed, his usual smile a ghost of itself on his lips as tension wavered all around him. “He can’t see you properly through me. That’s irritating him. He’s hungry for your details. It’s been a long time since I’ve dared to bring someone home.”

“So he’s — carving up and eating my emotions?”

“Tasting,” Sideswipe said, as if that should be significantly less disturbing. “Getting the shape of your character. How you move through space. How you react. How you panic. How you laugh. Feel… Love. It’s how he sees through me when I’m merged with another. It’s just a little taste.”

Each word meant for comfort dragged Prowl deeper into a place he didn’t have the memory architecture to describe.

Feeling deeply exposed, helpless, and violated at such a fundamental core level, Prowl could no longer suppress the shudder Sideswipe held in him from transiting through his doorwings —

The vibrations of them stirred with in him.

And the fingers combing curiously through Prowl’s spark froze.

“Sunny… wait,” Sideswipe’s words pulsed in an ominous bass of warning. “Let me explain before you —”

The warming touch turned back to ice. Colder. Until they burned. Crystals of ice crackled up the dissected ribbons of him, twisting through fingers like they were cording through internal wires.

Then yanked.

Prowl screamed, back arching, vocalizer spitting static — certain his doorwings had just been ripped clean off.

“Wait —” Sideswipe’s voice thinned, faded, the waveforms of him were decaying through a long hollow tube. “STOP!”

The freezing claws closed around Prowl’s spark, biting into it.

Its spin stopped, and Prowl lurched forward, crystal pressed tight beneath his bumper —

A surge of violent emotional torque buckled Prowl’s knees. His entire self tilted, as if his identity had been scraped out and hurled in the opposite direction.

The world flipped along with its colours into the inverse negative.

Prowl hissed, curling in on himself. Ribbons of his spark’s waveforms hanging from his back. It hurt. Primus, but it hurt. Like the way Sideswipe embodied an entire space with life and rhythm had been ripped out of the world, and all that was left was an audial shattering vacuum.

Wincing, Prowl opened his optics, looking up to confirm what he already knew.

Sideswipe was gone. His protection broken.

In his place stood —

The gravitational mirror. The opposite spin. The frightening, terrible symmetry of the half-spark city speaker Praxus had been pushing Prowl’s decision making toward.

In that instant, as their resonance crossed the impossible chasm into the rift torn in reality that should have separated them, Prowl knew him.

Sideswipe’s twin.

Sunstreaker.

Where Sideswipe was motion — heat and sound and flickering laughter through the thermals and dust strewn winds — Sunstreaker was an ominous void of hollowness.

The deceptive stillness of a riptide threaded between a crashing break.

The moment after lightening split the sky, and before the ground quaking crack of thunder.

A drawn vent, an impassive hand around a neck choking prey that shook in its silent death rattle. He was the lurch in a spark between seeing the flash of a missile launch and waiting for the inevitable strike.

The silence that shook harder than an audial splitting roar.

And found in those moment of ominous, terrifying calm —

Fury. Vengeance.

War.

Countless lifetimes of it.

The impact of the frontlines lived in the hollow of him. It was the calm. Pressurized rage from being trapped fighting an endless battle, packed so tight it no longer had shape. Only temperature. Only a force within a vessel threatening to deform it until rupture.

“You’re a Praxian.” Sunstreaker’s words were deceptively soft.

A tidal zone pulling back in the dead of night, waveforms overlapping, building a destructive crest that traveled unseen, deep beneath the sea’s surface.

Prowl could feel the building pressure wave.

Nodded, trying to reclaim his motor control.

Make his offer of what a mech who had become divorced from his interest in individuals, beyond Sideswipe, and only knew consumption might want. Be useful. Stroke his ego. Suck up to him — but don’t lie to him.

“Sideswipe said —”

“A lot of things he’s convinced himself are still true about how he feels about you, I’m sure.” Sunstreaker's voice was monotone and blunt. His fingers tightened on the top of Prowl’s helm’s crest, jerking his head back and keeping him on his knees. “Easily rectified. His attention span is so fleeting. So fickle. Once he’s back with me.”

“I can get you wings for your garden,” Prowl said, quickly. “Seekers of Vos. Their Air Commander. Their entire air force. Together, we can lure them into the Rust Sea for you to do with as you please. They will not be missed, and I’ll owe you a favour.”

“Tempting,” Sunstreaker said, though he barely considered it. “But I find my inspiration has suddenly shifted to a desire for fresh Praxian wings.”

Sunstreaker’s extinction-laden stare carved over Prowl’s shoulder, then dropped to the shard of crystal clutched in Prowl’s hand. Unlike every other colour, it hadn’t flipped to the inverse. It was still blue.

The light with in the crystal fragment met Sunstreaker’s stare, and pulsed as it wove its ribbons beneath Prowl’s bumper. Twinkled a little symmetrical pattern. As if giving a cheery greeting. A wave hello.

Sunstreaker winced. His blank expression cracked, contorting in a tsunami of pure rage. It crashed over Prowl. Slamming into him, a blunt force trauma delivered directly to his spark.

Prowl gasped, Sunstreaker’s bitter betrayal searing into him, mirrored in his spark. The electromagnetic lash held him down, a rolling riptide of agonizing pain. Prowl’s systems buckled, his spark spiraling out of sync, its rhythm shattering against the tide of Sunstreaker’s vengeful storm surge.

He couldn’t cycle air. Couldn’t think.

Each internal function began winking out, fought, then failed. He was being dragged out into nothing, stripped of himself — his very being — unraveled thread by thread.

Drowning. Choking in his own dying waveforms.

The cold embrace of obliteration tightening around his spark.

Then — an all-consuming warmth.

Strong arms wrapped around his waist, reaching through the core of him — through the tangled mess of him — a desperate grip fighting against the terrifying magnetic pull. He was caught and hauled out, reality bursting back into shape, dragged from the abyss to a solid, familiar shore.

A melodious voice, impossibly gentle amidst the storm whispered against his helm, rearranging him, and holding his cracks from spreading until they healed.

“You’re okay, Prowl. You’re fine. Vent. It’s over now. We made it.”

Sideswipe clung to Prowl on the berth in his private quarters like it was his life that depended on it, and not Prowl’s.

Coiled in a tight ball, Prowl shook, coolant dripping from his optics, vents heaving and gasping around the ache of his stretched and torn spark. It still spun wrong — too fast, too slow — caught in a chaotic syncopation that didn’t feel like his natural melody anymore.

“He was inside me,” Prowl whispered, horror struggling through the static haze. “Your brother. He was inside —”

“I know,” Sideswipe said softly, too softly, vents warm against Prowl’s helm as he hugged him tighter, petting down his back. “He didn’t mean harm.”

Didn’t mean…

Prowl pushed Sideswipe away, ripping out of his arms. Away from his touch as he wiped at his tears. “He tried to drown me in my spark’s own wave functions!”

“And I saved you.” Sideswipe reached for him again, and Prowl viciously bat him away.

“You held me in place to let your twin suck on my emotions like a rust stick!” Prowl snarled, his engine roaring. “Then he tried to kill me!”

Sideswipe didn’t flinch. His gaze was calm. Steady. None of this surprised him. As if he already knew this truth was an inevitable probability that couldn’t be escaped, and had moved past it.

“In war,” he said patiently, as if speaking to a New Build, “a narrow escape with your life is still a victory.”

He slipped a finger between Prowl’s legs, trailing it up through the physical mess made of their shared overload during their merge.

“Why not in love?” Sideswipe asked, raising his finger it to his lips, sucking it clean. He leaned forward, then, and placed a gentle kiss over Prowl’s exposed spark. “In peace?”

In the glow of Prowl’s sparklight, Sideswipe’s expression was exultant.

Victorious.

This was part of Sideswipe’s terrifying split-spark nature. He was incapable of finding fault in Sunstreaker, no more than Prowl could rage at the wind. His twin was a natural force imposed upon him and his existence.

For Sideswipe, it was like being angry at gravity when something was knocked off a table.

Of course the object was going to fall.

Of course Sunstreaker would try to kill Prowl.

But he didn’t. So Sideswipe didn’t see a reason to be angry about it.

“Are you scared of me yet?” Sideswipe asked.

“Terrified,” Prowl answered, seeing Sideswipe now, in a way that could never been unseen —

And Sideswipe’s shoulders actually slumped. His expression crestfallen. He sat up and went to rise, but Prowl pulled him back by his forearm. Cupped his hands on either side of his face. Stroked down his cheek.

“But not of you,” Prowl said.

He was terrified for Sideswipe. And of this life. This prison of symmetry caged around him, forever sharing his most delicate and private of emotions and moments, bonded and entangled to one he never chose.

Destined to always return to his side.

Trapped by fate.

It seemed a torture to Prowl.

To Sideswipe… it was just who they were.

“I —” Sideswipe hesitated, emotion trapped, swirling behind his optics he didn’t know how to translate out loud without his language. He swallowed. “Do you love me?”

Because outside of a merge, Sideswipe could never be sure. No matter how hard either of them tried, Prowl would never feel more real to him than his twin.

“Against my better judgement,” Prowl said, shaking his head at himself. “I’ve… grown fond of you.”

“Good,” Sideswipe said, the tension in his frame leaving, relieved. Then gently, he closed Prowl’s armor, walking his fingertips up to Prowl’s hardline ports along his neck, stroked them, and smiled. “Because I accessed your command codes.”

“You… what?”

“To order an evacuation.”

Prowl blinked. The words didn’t compute, not at first. His own authorization had been used without consent, and still Sideswipe’s voice was gentle and loving.

“There’s a single transport left,” Sideswipe went on to explain. “Smokeshow’s holding it for you.”

“Smokescreen,” Prowl corrected in a hiss, “And “what?”

“You have to go.” Sideswipe pressed his hand over Prowl’s spark. “My brother’s coming, I’ve really pissed him off this time.”

“I thought he couldn’t leave your city while you’re out. That he’s trapped in the rift with your city.”

“He can’t,” Sideswipe said, turning away to stare out over the sea. “But he can bring her here.”

“Then why run?” Prowl asked. “I thought she wanted to re-establish relations… with Praxus...” he trailed off, knowledge of everything he’d learned in the merge, of Sideswipe’s urgency, and Sunstreaker’s violent emotional reaction to the presence of a Praxian being brought there making a sudden, terrifying sense. “You lied.”

“I lied,” Sideswipe echoed, unapologetic, as if that too were simply part of his nature, and Prowl shouldn’t be surprised. “Stormsinger’s never forgiven Praxus for his indiscretions with Vos. For allowing his hands and optics to wander. She’s furious with me right now — and with Sunstreaker on her side — well… I won’t be able to calm her to explain who you are, not without calming Sunny first. And it would make my life a lot easier if I don’t have to protect you at the same time.”

“Easier?” Prowl balked, shoving Sideswipe by his shoulder. “Make your life easier? You’ve undermined my entire command! Betrayed my trust — you —” Prowl stopped, taking in the sight of Sideswipe, sitting there on his berth, looking as if everything was going according to his plan. “You still don’t think you’ve done anything wrong.”

“Nothing’s gentle about war, Love,” Sideswipe said, tossing Prowl a conspiratorial wink as he reached for his hand, pulling it toward himself. “Why would the same be true about peace?”

Doorwings steady, Prowl held the unblinking gaze of Sideswipe's smug blue-green optics, allowing his hand to be raised to Sideswipe's lips —

Then engaged his enforcer protocols, cracking open the instructions that had lasted, dissolved from the why, through sands of time…

On how to contain a rogue split-spark twin.

Chapter Text

Prowl restraining Sideswipe with his old, boring, cybersteel enforcer cuffs, and entangling him within a physical chain net, was clearly not part of Sideswipe’s plan.

It had been surprisingly easy to bind him — such was his ego and unflinching confidence that he was in control: he thought Prowl had been clamoring for one last circuit blowing round with him. Prowl, himself, recycled Sideswipe’s own words to him: saying he was being ‘creative’ with their use. Elated, Sideswipe was easily led astray by the risk of squeezing in a victory lap just before his finish line. Once Sideswipe realized what Prowl was actually doing, it was too late. Sideswipe was trapped in restraints so simple and primitive, he could not harmonics his way out of them.

Unfortunately, his mouth still worked. Even after Prowl had called in three of his soldiers to stand guard, Sideswipe kept trying to talk ‘sense’ into Prowl — insisting Prowl had to leave; to get on the transport before it was too late. His words were still too loving. Too gentle.

And utterly enraging.

Prowl shoved a cleansing cloth into his mouth.

“Mmrfh —!”

Then he taped it shut. Silver adhesive, right over his lying, traitorous lips. That shut him up.

Mostly.

Sideswipe found other ways to make his unrelenting manipulative presence known. Namely, trying to follow Prowl — while cuffed and tied to the chair.

The rubber-capped feet of the steel chair scraped and squeaked across the floor as Sideswipe scooted micron-by-micron behind him, making shrieking sounds like a trapped, dying turborabbit with every shuffle.

The commlines buzzed with active channels — far too few voices as Prowl’s remaining soldiers tried to re-establish connections with outposts that had gone dark. Prowl grit his teeth as he heaved his dual-mounted thermal missiles over his shoulders, locking them into place with a determined snap.

Another squealing, dying shriek behind him announced Sideswipe’s continuous murder of Prowl’s once pristine and polished floors: his impeccable record, now streaked with matte black skidmarks.

Prowl turned, flaring his doorwings and armor in warning. Under the force of Prowl’s iron glare, Sideswipe froze.

“If he moves,” he said to three of his ten remaining soldiers, “if he so much as hums a jaunty tune: shoot him.” Prowl jabbed a finger in the centre of Sideswipe’s thick, red chestplate. “Right here. In his cursed, lying spark.”

The soldiers in the room, their weapons charged and aimed, may as well have not existed for all Sideswipe kept his unwavering optics on Prowl. They shifted from their lightest saturation of blue, bordering on white. Bleeding charge in building panic. Pleading.

Doorwings straight and unyielding, Prowl turned, then snapped a final order at his soldiers over his shoulder. “Blindfold the fucker too.”

Prowl stalked out of his private quarters, stopping long enough to upend his table, sending the expensive crystal tumblers crashing to the floor. He ground the shattered shards carved from the Crystal Gardens under heel and wheel as he passed. His hands clenched in and out of fists as he seethed.

How dare he.

How dare Sideswipe undermine Prowl’s command. His trust in him. His judgement.

His spark.

The hallway was unnaturally quiet for a base on high alert. Upon Prowl’s command, the evac sirens had been silenced. Pink rectangular lights flashed along the ceiling in a high-pitched, clicking buzz. Prowl’s determined stride, laden with full armament, echoed under each step.

A hollowed out crew. A compromised commander.

So much for Prowl’s first command acting as a keystone to solidify a defensive barrier around Praxus. Sideswipe had managed to undermine every outpost along his shores.

Outside the windows, the Rust Sea appeared calm, but Prowl knew better. It was taking a deep, vacuumed inhale: Sunstreaker, a vessel of pressurized rage. He was moving his city — and the rift she held — here.

Past the boundary line.

Into the foothills of the Manganese Mountains.

There was no telling what kind of long-term damage that would cause. In all of recorded history, in all of the myths, the Hexagon had never crossed the boundary line.

Stormsinger had never left her sea — the defined three-dimensional plane her split-speakers used so she could safely phase in and out of their dimension. Holding the rift from consuming Cybertron, and spreading rusted decay.

Projections of what Prowl knew of Sunstreaker, Sideswipe, and their frontline warrior city-Titan — their language, their technology, their quantum-connection to each other and their symbiotic relationship to a conscious, living, quantum-computing city that held a dangerous rift torn in the fabric of reality itself — churned through his neural network, and the fragment of Praxus —

Her once lover, stitched and soldered into Prowl’s own neural network — living in his head

— in addition to the base-wide chatter over the comms. While also needing to communicate and direct his soldiers in the physical realm.

Smokescreen fell in beside Prowl, pulling up a tactical feed on a mobile display. As if Prowl would need it.

As if he was bound to be unable to handle the mental load of the variables he needed to track contained inside himself alone.

As if he didn’t have a fragment of a tormented and traumatized quantum-computing Titan installed into him as a secondary support network.

“Twenty minutes after the evacuation was called, the Hexagon ate its boundary hurricanes,” Smokescreen said. “It’s shooting toward us, now, building speed. Estimates say it has broken the sound barrier, but it’s hard to tell with the magnetic interference lagging our satellite feeds. By the time we got a clear signal, it’s like it had teleported to a new place.” Then he lowered his voice, doorwings tense. “I really thought the evac orders came from you.”

He kept trying to apologize, but this wasn’t his fault. This was Prowl’s oversight. His command. His burden to bear.

They passed another blast door where the last of Prowl’s support crew — the grand total of two of them — were stripping unnecessary hardware to reroute more power to the shield generator. They didn’t pause to salute.

And Prowl might have shot them if they had.

By the time Prowl had learned of Sideswipe’s betrayal, the Hexagon was no longer a hexagon, and had already begun its path. Before the signal disruption started, the satellite feeds had showed it with chilling clarity: a trail of red-rust destruction, lightning and torn cloud bands, tracking in a near straight line.

The dust trail of something monstrous, and with far too many legs, running at full speed over the surface of the sea.

“How many outposts have gone dark?” Prowl asked.

“Seven,” Smokescreen said, slower than the part of Praxus reported a different number as his own thought. “No, eight.”

Prowl’s hands clenched in and out of fists again. There was no way to confirm Sideswipe’s routing orders and how many transports from the other outposts had gotten out.

The magneto-static interference had blown out their comm tower network. They were left with localized line-of-sight.

Sunstreaker’s doing.

Prowl was certain of it. The mirrored twin did not intend to let word of what would happen here to spread beyond rumors and myths. Sideswipe had left their hidden Titan’s flank exposed, broken their shield of isolation, and Sunstreaker was coming to close it.

By killing the one who had opened the box, intending to release what was inside.

“We could just toss him out there,” Smokescreen said, carefully watching Prowl from the corner of his optic to gauge his reaction. “My bet’s on it tracking to him, not us.”

Prowl knew Sunstreaker was. And he had run the calculations and sent one of his three remaining gunners to the armory to assess if they had enough missiles to strap rocket boosters on Sideswipe, and launch him back into his cursed sea as a payload.

Ideally, at Vos. Let the heat and magnetic distortions of the rift rip them from the sky.

The triangulation had already been mapped.

The straight-line rust storm had become like a compass needle magnetically aligned to Sideswipe’s precise co-ordinates.

Sunstreaker was guiding Stormsinger by the metaphorical ‘string’ Sideswipe had mentioned to Prowl during their merge. The one they used to navigate through poor visibility when Sunstreaker felt a strong emotion, and they overlapped.

It worked out here too.

To guide Stormsinger through their physical dimension, and to not lose her, leaving her forever voiceless as she continued to hold the rift, for a second eternity. This time, alone.

“I’m keeping it in reserve as a final distraction for evacuation,” Prowl said, not slowing as they approached the command centre’s doors, “once all other options are exhausted: we launch him as close as we can toward Vos.”

“And what are our other options exactly?” Smokescreen asked. “We can’t fight an entire city cloaked in storm. Let alone one that can survive in the Rust Sea.”

The command centre door hissed open.

“I need to talk to the city within the Rust Sea,” Prowl said, loud enough for all inside to hear. “She is a powerful, quantum-rift shifting Titan that creates the storms.”

Inside the command centre, Datarider was already halfway out of his seat, rubbing at his silver chevron.

“Sir,” Datarider said, continuing the conversation Prowl had been having with him through comms outloud. “I’ve —”

“Already exhausted all known frequencies on short-wave line-of-sight transmission as our long wave communications network is down and there’s too much interference to bounce a signal off the atmosphere, I know,” Prowl cut him off. “What do you know about crystal-based, quantum-harmonic, sixth-dimensional geometric frequencies?”

“Uh —”

He had been on the comms with Datarider the entire walk here about opening a short-wave communications frequency into the storm. He had already sent him the files of the language he’d been translating.

Primus, could no one keep up?

Sideswipe can.

Prowl shoved that errant probability Praxus threw his way, and gestured to the last updated satellite image they had of the Rust Sea.

“Stop taking his side,” Prowl snapped back at the Titan’s fragment in his head. “This is your fault too. What exactly did you do to make her this furious at you for this long?”

Parasitic system corruption.

Was the highest result by a significant amount, so Prowl focused on it, and asked for a definition.

Symbiosis in retrograde.

The highest probability given for an answer offered no clarity, nor did the next result.

Broken oath: her split-speakers suffered.

Trying to find a way to solve the ancient city-Titan relationship drama before Stormsinger arrived — and Sunstreaker maliciously encouraged her to stomp on them all while blasting them into fragments — was just another permutation Prowl had to keep running in the background of his operations.

Both him and Praxus’ finger of a fragment installed and welded into Prowl’s head were getting increasingly frustrated with each other’s limitations. With the way this attempt at a conversation was going, Prowl was becoming increasingly convinced he’d been installed with Praxus’ middle finger, specifically.

Query Sunstreaker: he is her honour. became the highest probable result that refused to move from the top of the probability stack as it became useless to ask any further clarifying questions. The second being: Sideswipe will deceive: he is her shame.

Prowl internally snorted at the insistence that Sideswipe had shame, and Sunstreaker was in any way honourable. But, he didn’t disagree with the stalemate they had reached. He didn’t trust any answer Sideswipe might give him if he asked what a ‘parasitic system corruption’ was. At this rate, Prowl thought he would actually be better off trying to get a direct and blunt answer from Sunstreaker — before he blasted Prowl to dust and presented the pile to his twin to play with, and dry his tears.

At the same time Prowl wrestled with the limitations of the fragment of Praxus in his head — in an effort to determine the best course of action to defuse Stormsinger’s fury — he addressed his soldiers.

“An ancient, sentient, quantum-computing Titan, a veteran frontline warrior of the legendary Quintesson-Titan war, is racing toward us, commanded by an unstable, vengeful — and in the interest of being concise to bring you all up to speed — let’s call him a demi-god: a personification of terror, destruction, vengeance, and war.”

The room fell silent. Stilled. All optics and visors reset. Blinked. Flashed. Staring.

Prowl didn’t flinch.

“Our esteemed guest, the god of war’s split-spark twin — a cursed and forsaken personification of chaos and misdirection — has pissed him, and their battle Titan, off. Making the fall out between them our problem.”

Twin? God of war? Titan? Smokescreen mouthed, confused, as his hands tightened on the external screen he was holding. The display distorted in a way Prowl was certain Smokescreen was fearing of him.

“And?” Datarider said, black doorwings twitching in contrast to his blue chest armor and shoulder pauldrons. He had always trusted Prowl and his predictions implicitly, but he was clearly confused what his commander expected him to do about the strange new reality he presented.

“And I need to talk to the enraged city-Titan to calm her down.”

Because I have a piece of her once-lover in my head, and I am Praxus’ only hope to heal relations between them, so he can ask for her aid.

Prowl was not foolish enough to say that part out loud. He hadn’t even had the time to reckon with the terrible horror of it himself. He was the absolute worst bot to land the fate of guiding Titans through couples therapy. He didn’t even know if consent mattered when a Titan sent their Speaker to reconnect… physically. His fuel tank and spark dropped into a void.

What if Stormsinger assigned Sunstreaker for the task? How was Prowl expected to manage to —

“Uh…” Datarider rubbed at the back of his neck. “I guess I could try geodesic lattice harmonics with the patterns you sent?”

“Don’t guess,” Prowl said, shoving that mortifying horror too into his emotional storehouse he refused to open for fear he’d crumble. “Do. Find a way to transmit those symbols, translating them into waveform vibrations the Titan can feel to know we are here.”

“Yes, Sir,” The communications officer sat back in his chair, fingers flying across his console.

A burst of feedback rang through the overhead speakers. Then static — crackling, full of background noise that sounded like crystals shattering —

“While you do that,” Sideswipe’s disembodied voice said as the static cleared. “This cursed and forsaken personification of chaos and misdirection is going outside to see if I can talk the god of war down — and when he’s in a better mood, I’m telling him you called him that; he’s going to love it — but having your toy soldiers try to kill me is not helping in that regard! He can feel that, you know!”

The moment he heard Sideswipe’s voice, Prowl’s entire frame clenched in rage. He had already pressed his finger to his audial as he spun on his heel, opening a direct channel to the guards he had left surrounding Sideswipe.

“I ordered you to shoot him in his spark,” Prowl said, snarling into his comms.

“We… uh, did. Repeatedly.”

A high pitched whine came from Prowl’s arm as he primed his weapons. “And?”

“It didn’t stick.”

He transformed, and tore through the halls, clearing two security checkpoints, the blue and red of his sirens lighting up the ceiling and the walls while Sideswipe was still talking.

“What do you mean, it didn’t stick?” Prowl hissed, seething.

“He wouldn’t stay dead, Sir,” came the reply. “Said we were just pissing his twin off more, and to tell you for what it’s worth, he’s sorry.”

As Prowl slid toward the door to the landing platform, he transformed. His mind, body, and spark halting in its tracks. “He apologized?”

The landing platform’s blast door opened on Prowl’s transmitted command.

And there he was.

Sideswipe, one-half of Stormsinger’s split-speakers, walking toward the crackling green glow of the electromagnetic shield dome.

Edges of him curled in smoke. Paint scorched from blaster marks. Metal exposed and patchily healed. Cooling weld-lines shimmered, knitting across his chestplate like molten scars. Through the cracks, his beautiful — terrifying — cursed-spark spilled out of him in faint glowing light-beams, catching the dust that had been trapped from returning back to the Rust Sea.

And he was staring up as the calm before the storm began to break; as the sky was reclaimed by clouds —

At the fading stars.

Prowl leveled his weapon, target locked. His finger twitched on the trigger as if he could simply shoot how the sight of Sideswipe made his spark leap, and kill the feeling inside himself he couldn’t be certain had ever been his.

“Sideswipe, stop.”

Sideswipe’s mouth formed a grimace. He winced, hunching in, and took a further step toward his sea.

Prowl stalked forward, the charge of his proton blaster rising to its highest setting, and his thermal missiles beeping as they locked in on target. “I said: stop!”

Sideswipe stopped.

He turned slowly, hands rising: the red light of his optics burning in the shadowed half-light beneath his helm. The line of his mouth was tight with pain as his optics met Prowl.

“It would be easier,” Sideswipe said, quietly, “if you’d just evacuate. I can still hold them off until you and your soldiers get clear.”

He flicked a glance toward the last transport, plugged into the generator, and fully charged on the landing pad. Then, he looked back out at the sea again, as if it were calling to him: a sorrow of pre-destined inevitability seeping from him that Prowl was determined to ignore.

“I need you to open a communications channel to her for me,” Prowl said, unwavering, words forged in iron. “Be my translator. Now.”

Sideswipe shook his head. “When I’m out here, my communications with her get filtered through my brother.”

The air warped from the heat of Prowl’s weapons as he stepped closer. “Then give me a frequency, a conduit to her, and I’ll do it without you.”

“That’s not how it works.” Everything about Sideswipe had become maddeningly soft, even his attempt at a smile for him. “At the dawn of the Age of Titans, she burned out every City Speaker candidate sent to her as an offering: until Sunny.”

“Then tell him to open one,” Sideswipe’s quiet refusal to harden made Prowl activate his missile pre-launch sequence. “Tell him Praxus has sent me. Tell him Praxus has suffered in silence long enough. Tell him Praxus seeks forgiveness and penance for the broken oaths that caused the suffering of her split-speakers.”

Sideswipe winced hard at that, grimacing. “He won’t listen. He’s too mad at me.”

“For conspiring with a Praxian spliced into a mutilated piece of a Titan?” Prowl said, snapping at him. “You know I didn’t ask for this piece of Praxus in my head!”

“For doing something so painfully mortal as fall in love.”

Prowl’s grip on his gun trembled; his missile launch sequence halted.

“Sideswipe —” his vocalizer crackled in static. “We can stop this. My predictions aren’t wrong. Vos’ seekers will not divert around Praxus the day they finally launch an attack run on Iacon. We cannot let Cybertron fall into an endless war. You have to give me something.

Sideswipe took a cautious step toward Prowl.

Then another.

Closing the distance between them until the heat of the muzzle of Prowl’s gun warped the still-glowing, healing fracture in Sideswipe’s chest armor.

The barrel thudded against him in the smallest of vibration, Sideswipe unflinching from the heat the weapon searing into his partially exposed spark.

Prowl’s finger twitched on the trigger. He didn’t fire.

Sideswipe’s fingertips brushed along the barrel, a static discharge trailing in their wake, coaxing the charge out of the weapon, and slowly, he pressed it down. His charged palm found Prowl’s Autobot insignia — heat-to-heat —

Palm sworn to spark.

“I already have,” he whispered in his native tongue, filling every void between the 12 chord scale with the depths of his turbulent emotions.

In answer, a familiar, new pattern pulsed across Prowl’s spark chamber —

“… what?” Prowl hadn’t held anything in his hands when Sideswipe pulled him out of their merge. He couldn’t have brought the crystal’s pattern out of the merge with him — could he?

“Be patient.” Sideswipe’s helm dipped, brushing the top of Prowl’s like a conductor laying down a final mournful note; one that would linger inside him long after the symphony’s end. “Time moves differently for me when I’m near him. Sunny and I… we have a way of consuming each other.”

Outside the shield, the wind picked up, flashes of green carving the edges of Sideswipe into focus.

“If you can manage to trust only one thing from me,” Sideswipe swallowed, the segmented armor along his throat bobbing as he pulled his helm back, blue-green optics refracting in tears he could never afford to shed. “Believe this: I don’t want to see Praxus dragged into an endless war anymore than you do.”

One hand rose, cupping Prowl’s face, thumb grazing the base of his chevron over his left optic. Static leapt across the seam where his fingers touched, grounding his charge into Prowl, bleeding it into his optic, through Prowl’s neural circuitry —

Into Praxus.

The world shifted. Vision knocked out of time. A vent hitched as memory folded open, drawn from Praxus, and stitched together with a memory packet Sideswipe had left inside Prowl.

The parallax light of stars spiraled, their waveforms reaching back to their light source.

To before a time of a more primitive Cybertron. To its creation.

Of those who would one day being known as Cybertronians, sparked by the All Spark and altered to function by Vector Sigma, not as individuals but as categories: sorted, matched, and marched like drones into cities built as cages. Overseen by the many-faced horrors who whipped them into lines, working until their optics burned out, replaced without care. A seemingly endless stream of disposable workers and living weapons working to exhaustion beneath a sky writhing in the tentacle cables of their oppressors.

Judgement was passed upon world after world. Armies and workers sent forth to strip-mine the galaxy of its will to resist.

Then, another memory fragment.

A hand, familiar yet not his own, trailing the warmth of a faulty conduit. A pipe humming off-key, off tune with itself. A calling. A guiding rhythm, pulling deeper into a city’s arteries. A face of a Titan, larger than a mountain. A flash of light from lines on the floor —

The sudden awareness of form: a quantum existence knitted into a body that was also a city, a city that was also a cage.

Observed through the optics of another, Praxus awakened to the shape of himself in the universe.

Not as the machine the Quintessons had created: a weaponized engine of calculation to map the probabilities of planetary resistance to destruction — he was something more. A being that understood the probability of choice. A vast tactical mind that could weigh futures, and in them glimpse not only the path to devastation he was forced to choose, but the pathways he was not allowed to follow.

The roads that led to peace.

Symbiosis.

That very fraction of a glimpse in which he perceived himself and the destruction he wrought through the optics of a three-dimensional being, created a new pathway to harmony. One that Praxus’ first Speaker spread like a virus of dangerous new ideals to the other Titans.

They called forth their own Speakers, and became self-aware.

They met in secret, this Council of City Speakers. Disappearing from the sight of their enslavers around corridors as the walls or floors shifted into secret pathways. Gathering resources. Spreading the growing network of rebellion. Guided by Praxus’ vision they developed their own way to make their numbers grow.

And then, another memory — not of Praxus, but Sideswipe’s. Of him and his twin, small, raised in secret corridors within the Titans among the other spark-borns, free of Quintesson programming. Of him standing at a viewport and trying not to crumble in terror as he watched the launch of his twin being sent off world as an offering to the Titan who kept burning through her Speakers. A gift, hand-selected to guide her path by Praxus himself.

One she finally accepted as worthy of her power.

Then of Sideswipe’s helm pressed to a red chevron in stolen clandestine moments. Sparks merged. Whispers passed along Sideswipe’s hidden quantum-entangled spark-channel to his twin stationed far away.

The patience of a Titan is not linear, but to extract their physical forms from the Quintesson’s control, they had to wait for that one calculated instant Praxus foresaw when the Titans would rise to victory.

When it came, dust boiled on the horizon.

Kaon and Iaconus braced each others forearms through the planet’s crust. Massive forms pulling free of their bondage, their first steps shuddering across the surface of the Quintesson’s home world. Citizens sheltered inside them, staring in awe and terror as their prisons transformed around them into colossal beings who became known to them as their gods.

Titans, and their demi-god City Speakers.

The memory unfolded further.

The Quintesson enslavers did not hesitate to quell their rebellion. Their armada poured in from across the cosmos, so thick it blotted out the light of stars. Praxus had predicted the blockade, had calculated their enslavers’ response to press them back down. The Council of Speakers pushed forward, plowing through the first of the scattered Quintesson ground response. They guided their Titans to gather, their colossal bodies combining amid their stored resources to form a new world.

A refuge of defiance.

Cybertron rising.

Trapped, with no where to flee.

A single spark-born mech stood far outside their gathering. As if standing guard against the horde of Quintesson ground and air forces closing in. He looked up, blue optics turning red in the shadowed half-light of his helm as he smiled —

And a tremor of light split across the Quintesson home world from beneath the ground behind him.

A rift.

A wound in space.

From it she came.

The Titan who had never known a planet’s gravity. Their frontline warrior. Stormsinger.

Not walking forth, but crawling on twelve vast, segmented limbs: each cable thicker than towers, anchoring her gargantuan weight against the edges of the dimensional tear. Her rising armor not made of metal, but crystal hardened by cosmic radiation; impermeable to astroid strikes. She was black as space, refracting starlight into swirling storms that split reality itself. A living prism that sang in the universe’s fractures, her waveform calculations tearing through dimensions.

Praxus had never seen anything more beautiful through his City Speaker’s optics.

Exalted in their reunion, her Split Speakers moved with her, streaks of lightning across the battlefield. They carved her path with the blades she’d forged them, void blades. Compressed pockets of unreality. They arrived on flashes of her lightning as she split theirs. Her footsteps, their thunder.

They alternated through her portals, stepping in and out of her.

Never sleeping. Never tiring. Never dying.

A perfect symbiosis.

With them singing her way, she cut through the Quintesson armada’s blockade: flinging space bridge after space bridge as whirling saw-blades no armor or shield could stop.

The Titans were safe to continue to build their new home world at the epicentre of her spiraling, writhing cosmic storm. Iaconus and Kaon viciously cutting down Quintesson ground forces and any that fell through Stormsinger’s lines. Vos providing air support and creating distractions with their hard-light holograms. Helex and Tarn weaving their planet’s architecture from the materials stored from their factories. Kalis, Polyhex, and Nyon igniting the power of their cores. Praxus, the tactician puppeteer who engineered it all.

For the first time in their existence, the Titans tasted freedom.

As did their awe-struck, confused, and terrified citizens who’d been born of the All Spark.

The vision cracked — light spilling out — falling into fragments of the melody Sideswipe was weaving as he guided Prowl back out the fragment of Praxus.

“Cybertron was his vision of peace,” Sideswipe said. “We’ll save him. I know at the core of her melodies, Stormsinger aches for him, and loves him still.”

He stroked along the side of Prowl’s face as if burning the contours of him into his memory.

“When he calls for her aid,” Sideswipe continued, “she will answer. Always. As she did then.”

He dropped into his native language, lacing each word in a deep bass-laden vow.

“And those who did this to you and yours will answer to us for their desecration.”

His vow woven of a cosmic crystalline melody hung in the dawn’s still air, refusing to move beyond this pocket of unreality Sideswipe had carved between them. Static of lightning charge leapt between his audial horns, his optics burning red — and the arm of Praxus within Prowl reached for him, charge jumping in arcs of crackling power racing beneath his armor. Dancing across his lips. His face heated, and he leaned into the scorching heat, aching to close and finalize the circuit —

“Sir —” Smokescreen’s sudden voice cut across the synchronous charge, and Prowl pulled back, too late, as his batch-mate skid around the corner.

Smokescreen halted, processor clearly catching up with what he was seeing — and cleared his vocalizer with an overly dramatic awkwardness.

Prowl and Praxus aligned, growling from deep within his engine as they snarled, “What?”

“We might want to consider that final payload launch option,” Smokescreen said, pointing beyond the shield dome.

Prowl turned in that direction.

A towering funnel cloud had begun to descend from the sky at the base of the mountain pass — slow at first, then with alarming speed. It twisted: a metal snaking cable cushioned by wind and grit, crackling with internal lightning at it touched down. Static sparked along the edge of the electroshield dome, already straining from the sudden drop of temperature as the tornado cut beyond the boundary line —

Directly toward their outpost.

Sideswipe sighed, releasing his hold on Prowl as he stepping back.

“If you’d just left,” he muttered, “I wouldn’t have to fight a fragging tornado for you.”

With no further explanation, he strode toward the electroshield dome. He hummed, and the green shield shimmered, fluttered with displaced light — and then Sideswipe was outside it, walking calmly toward the storm of his deep-space transport-hub city-Titan breaching beyond the safety of their sea.

Smokescreen blinked. “Did he just —”

“Walk through the strongest, cutting-edge of science shield the Autobots have, like it wasn’t even there?” Prowl muttered, crossing his arms, beyond annoyed to be left with so much charge still built within him. “Yeah, he’s annoying like that.”

“Oh, we’re gonna talk about that part later,” Smokescreen said. “I’m still stuck on the part where he said he’s going to fight a tornado for you.”

Smokescreen pointed beyond the column of destruction carving up the pass from the Rust Sea. Three more funnels were poised to form at the entrance to the Manganese Mountain’s foothills, piercing through the clouds like the claws of a vengeful god.

Or an enraged brother.

“Because,” Smokescreen whispered in a conspiring nervous laugh, from the stress of it all, as he elbowed Prowl. “How many of those do you want to bet your demi-god lover-boy there can take?”

Chapter Text

The first note was so soft it was almost nothing.

It dripped from Sideswipe. Ripples spreading through the sand in concentric circles, as if drops of liquid sound fell from his fingertips. One at a time. A single drip. Drip. Drip. The awakening of a storm. Light and serene. Steady. Falling.

Calm.

The tornado the size of a skyscraper roared toward him. Howling and snapping. Static in the air crackled and bit. Flashes of light scored from within. An electromagnetic, torrential spiral of terror here to rip rocks from their foundations. To file its path to dust. Shredding claws. Rending fangs. Rusted decay.

And Sideswipe walked toward it, poised. Footfalls measured. Unflinching in his confidence. No hesitation.

Calm.

With each step, the sand rose and spread in crests and valleys around him. Intricate geometric patterns clicking into the shape of his harmonics.

Prowl stared at it in equal parts wonder and tactical analytic dissection. Had the sand always done this around Sideswipe when using his power, like it had in the merge?

Probably. Except for their first meeting, when Prowl had detected there was something off about Sideswipe's gait, he had never seen the Red Split-Speaker of the Rust Sea walk on the lightly-coated mountain foothills that brushed up against his shores. Sideswipe had stubbornly stayed inside.

But Prowl had seen the evidence. The hints Sideswipe had left for him, little clues like crumbs fed to gain the attention of the sliver of Praxus inside him. Prowl had seen the patterns of Sideswipe's power form on the surface of liquid in a crystal tumbler. Held the evidence in his hand. And turned away. Discounted it out of fear, in favour of logic.

Cymatics.

The shape of sound. Vibrations made visible through a thin coating of particles, a paste, or a liquid. Sideswipe’s harmonic power made physical. Observable.

The exact science of it eluded Prowl’s grasp, but there was a pattern of logic to it he could feel. Sense.

Use.

What was sound if not the stirring of the air? A vibration of particles. A sequence of sharp compressions and long releases. Collisions of high and low pressure. Of oscillating, overlapping waveforms.

What was wind if not the same?

A building storm was like a symphony.

In the face of being stripped to wire and gear, Sideswipe first became the quiet patter of a rising storm. A slow first movement followed by a rising, increasing staccato.

The static in the air charged in an ominous sense of a looming rise of energy. A weapon. Loaded. Aimed.

The first solid rumbles of thunder rolled over the mountains as Sideswipe stopped.

Shifted his weight.

Took a deep vent.

Then began the second movement: sweeping his left leg back through the rusted sand patterns in a long, broad arc.

A combat stance Prowl didn’t know. A combination of grounding and coiling tension. A spring loading with potential energy.

The tornado bore down on them, a column that writhed to strike as a living mass of destruction, and Prowl predicted an eruption of kinetic energy from Sideswipe in response.

Instead, grounded, Sideswipe moved his arms in a series of circular arcs. His armored spinal strut undulating in the controlled full-bodied movement. Stirring the air to wind in a counter motion around him. Warming it up to him in the already oppressive heat. Attuning the waveforms to him. Deeper percussive beats rippled through the sand in fractal spirals.

The approaching thunder rolling out of the mountains arrived, increasing in pace and intensity. A drum beat of warning to back off.

Aimed at his twin.

To calm his city, Sideswipe had to first calm Sunstreaker.

They had spent their entire lives snapping, colliding, and chewing on each other's waveforms. And if Prowl hadn't been there to hear how hesitant Sunstreaker had been knocking on Sideswipe's door — how concerned and worried he'd been that Sideswipe had blocked their bond — Prowl would have believed Sideswipe calming Sunstreaker to be impossible. Not after experiencing Sunstreaker's unbridled, pressurized rage for himself.

Assuming Sideswipe did managed to calm Sunstreaker, and Prowl gained an audience with Stormsinger, then what? What was Prowl going to say to heal the harm done that had Stormsinger willing to burn through an emissary of Praxus to this day? What exactly had Praxus done with Vos?

Parasitic systems corruption.
Symbiosis in retrograde.
Broken oath: her split speakers suffered.

Sideswipe had winced when Prowl had mentioned the broken oath. It was something that hurt so deep within him, and brought shame to Stormsinger, that he’d lie about it to hide. It had to be more than just Praxus’ hands and optics wandering over to Vos. How had the split-brothers suffered?

Lightning flashed at Sideswipe as if tasting the air around him.

Query Sunstreaker, Praxus offered as the only solution with a high probability of success to Prowl again. He is her honour.

Prowl shuddered at the sensory echo in his spark of Sunstreaker sucking in parts of him. Tasting him. Peeling, sorting, and braiding Prowl’s emotions like he was entitled to help himself and judge anyone Sideswipe had taken a personal interest in.

He had been warming up to Prowl — before he realized Prowl was from Praxus.

A dusting of rust-sand gathered in ribbons, spiraling to alignment around Sideswipe — a sphere of electromagnetic power.

His soft voice held them, singing to them like they were friends of his, guiding them. They followed in the wake of his arms’ motions until they spun on without him. Sideswipe held out his hand and the ribbons of rust-strewn wind condensed. Took shape.

A small tornado, so tiny in his hand, he could crush it in his palm.

He blew on it, sending it outward to meet the one sent by his twin.

It grew. Picked up speed. Still dwarfed by its towering sibling, it tangled at the base of the rusted monster, spinning in the opposite direction. Twisted up its length, growing as it fed — choking its waveforms —

And dispelled it.

Palms down, Sideswipe lowered his hands. The new sand that had been sucked in beneath him flattened. The shapes and patterns in them erased as he blew out his vents.

Wisps of blue static charge curled off Sideswipe's audial horns as he turned: a teasing, gloating grin cocked and loaded, leveled at Prowl.

“Are you just going to stand there in a drooling stupor enjoying the view?” he asked, circling his hips to shimmy his aft while gesturing down at his frame. “Or are you going to finally get on that transport?”

Prowl’s mouth opened, already shaping a snarl — he hadn’t been drooling. He’d been speaking with Datarider, parsing translations of Sideswipe’s harmonics, analyzing every movement to find a counter, and actively trying not to think about the piece of Praxus in his head or how Sunstreaker had left Prowl feeling peeled open and exposed. All while simultaneously needing to think about the underlying source of the relationship drama between Titans, and how Praxus seemed convinced talking to Sunstreaker was the only path out of —

Overwhelmed with the onslaught of his suppressed emotions breaching the walls of his partitions, and the technical aspects he’d been sorting and weighing, Prowl lagged in his retort.

Smokescreen beat Prowl to a response.

“Personally,” Smokescreen said to Sideswipe. “I was planning on just standing here gawking. But if one slips by you,” he formed a narrow space between the palms of his hands, “make sure it’s one I can stomp on, and you can count on me for back up, deal?”

Thunderous laughter rumbled from Sideswipe, as Prowl elbowed Smokescreen in the side, causing his batch-mate to let out a sharp — oof.

“Do not inflate his ego.”

“Pretty sure you’ve spent the past weeks inflating parts of him enough for both of —”

Sideswipe let out a frustrated groan as he turned his head back and glared up the mountain pass at the Rust Sea.

“Not everything has to be an art project, Sunny.” He swept back his right leg, retaking his stance. “‘Battles are a transient space,’” Sideswipe muttered under his harmony in what was a startlingly accurate impression of his twin. “‘A loud rush of euphoria followed by a false safety of victory when you’ve won nothing.’ Blah, blah, blah. So predictable.”

His grin faded. His optics narrowed.

“And right on cue.” He glared out at the three clawed funnels forming with voracious power and speed.

The one on the left tore across the side of a mountain like an avalanche. The one on the right gouged a trench into the cliffside.

And the one in the middle was charging straight for them.

A hunting pattern. To take the territory Sideswipe had just defended.

Coming to flank him.

Targeting Prowl.

“What’s your plan, Prowl?” Sideswipe shouted back at him. “Leave? Or spend the rest of your short life watching me apologize by fighting tornados for you? Because when Sunstreaker punches through me to get to you: I won’t be the one who dies.”

Prowl swallowed, sending his fear back behind a partition by focusing on the highest predicted probability of success.

“I need you to switch places with your twin,” Prowl commanded, refusing to leave.

The power rebuilding around Sideswipe instantly died. “Are you insane?”

“I need to talk to him.”

“In case it wasn’t obvious,” Sideswipe gestured at the approaching avalanche sealing the mountain pass closed. “He’s less in a talking mood, and more of a —”

“Sand blast off my face, gut my internals, and leave me hanging by my dissected doorwings in a cave next to one of his mural shrines kind of mood?” Sideswipe winced and still, Prowl did nothing to soften his delivery. “Or how about a forcibly transform me into a shape that fits me into a crevasse kind of mood?”

“Those were extenuating circumstances,” Sideswipe said, hands clenching into fists.

“Because of the ‘parasitic system corruption?’” Prowl asked, and Sideswipe’s entire frame clenched. “Sideswipe: does Sunstreaker have a virus?”

“There’s nothing wrong with Sunny,” Sideswipe hissed, turning away from Prowl. “He just gets a little over protective sometimes. I can calm him down, but you being here is making it a lot harder.”

“What happened to Praxus’ last Speaker, Sideswipe?” Prowl asked. “Why is your city the only one who still has hers?”

Sideswipe didn’t answer, he was staring at the approaching attack formation like he wanted to let them take him rather than answer those questions.

Prowl was certain he already knew the answer. Could feel it, as if it was his face that had been sand blasted off that day. He just didn’t know why Sunstreaker had killed Praxus’ last City Speaker and left his remains, and those of his guards, mounted in that cave. Those deaths were violent and personal. A revenge killing maybe?

Query Sunstreaker: he is her honour.

… an honour killing.

The one responsible for the mural massacre site had felt vindicated in what he had done. Had taken a perverse pleasure in dissecting Praxus’ Speaker and entombing his guards.

Praxus was right, Sunstreaker would not hide from the truth of it as Sideswipe did. He’d gloat about it.

“Maybe stop upsetting the guy who’s fighting tornados for us,” Smokescreen whispered, then raised his voice and over-enthusiastically raised two thumbs up. “You’re doing great Sideswipe!”

“If you want to back me up, Smokeshow,” Sideswipe shouted. “Drag his stubborn aft onto the transport!”

“It’s not a bad idea, Sir,” Smokescreen said. “Look, Commander, we tried, but how does staying here and making a glorious last stand help stop the escalation of the war? He likes you, we don’t lose that advantage if we make a strategic temporary withdrawal while he calms his twin.”

That was a logical solution, and Smokescreen was choosing his words carefully to try to allow Prowl to save face under the collapse of his first command.

But there was another path.

If Sideswipe wouldn’t go back into his city, Prowl needed to find a way to draw Sunstreaker out, and pin him down in a targeting solution long enough to get his questions answered, so Prowl could defuse this. But how?

Sideswipe’s muttered words about his twin snagged in Prowl’s neural net.

So predictable. And right on cue.

“Get me a hardline cable to the base,” Prowl said to Smokescreen even as he dashed toward the transport.

No helm ache yet for how much he was feeding into his tactical network — that was strange. He took the absence as a small mercy, Praxus wasn’t overwhelmed by the physical sensations of a world he only theoretically knew, but the glitching would come if Prowl didn’t expand his capacity.

Soon.

The power cable to the transport ran in a long, black snaking line to the generator. Prowl crouched beneath the transport as he pulled it free — while he spat orders over comms to the techs: “Every scrap of non-essential power to the generator. Shut off excess draw. Now.”

Smokescreen returned, sliding in beside him, a data cable coiled in a death grip. Lightning from the clash outside the dome painted their armor in jagged flashes of hard light and shadow.

Smokescreen’s doorwings sank as he saw the power cable in Prowl’s hand. “You’ll fry yourself.”

“Not if I plug into the base first, and expand my neural network into it.” The fragment of Praxus said it would work.

“What’s the probability on that?” Smokescreen said, the bite underlying his words bitter.

“High enough for you to follow my orders,” Prowl snapped. They did not have time for this. Prowl tilted his neck to the side, exposing his ports. “Network me.”

The landscape flashed with more light, then shook with percussive thunder, the growing dawn smothered by a flat stormlight.

“It’ll be too much to process,” Smokescreen said, but he moved to comply, his shaking hand already bringing the connection into alignment.

“Not for me,” Prowl said.

The command outpost’s computing power was a small fraction of a city. And if Prowl could handle a sliver of Praxus in his head — he could support expanding his neural net through a peripheral network.

Give his severed limb room to stretch out.

“You better be right.” Smokescreen’s optics wavered, worry bleeding out with the static in his vocalizer.

“I’m always right,” Prowl said, flicking his doorwings back.

“You weren’t about Sideswipe.”

“He’s an edge case,” Prowl snapped, defensively. “A chaos particle —”

“You can’t predict chaos.”

“No,” Prowl said, lining up the high power cable with a charge port beneath the base of his helm. The seams between his plating prickling with charged air. “But I’ve solved enough murders: I can predict vengeance.”

He plugged in.

His HUD flinched in static as a resonance vibrated in his spark chamber, the unique pattern of that crystal Sideswipe had chosen to ignite from the others he cast off — Prowl’s visual feed resolved in time to see the oncoming towering funnels wobbling.

Their paths wavering. Slowing.

And the world as he saw it, convulsed with equations of light.

The power cable moved.

Swelling and recoiling like a feeding serpent along the ground as the electromagnetic field pulsed through it. Prowl blinked. Staring at the sudden flood of data, tracking even the flow of electrons into his frame.

“Commander,” Smokescreen gripped Prowl’s shoulders, his voice splitting in fraction of a second delays — heard both through Prowl’s audials, and from multiple microphones around the landing platform. “Prowl, can you hear me?”

“Yes,” Prowl answered, the word booming from the base’s speakers, and Smokescreen winced.

But Smokescreen’s wince was only a minuscule fraction of the data Prowl was now processing at a rapid fire pace. His command outpost was smaller than a city, and not sentient like Stormsinger or Praxus. There was no overwhelming presence of pressure pushing back on him — no, a fragment of that pressure had already lived in Prowl’s head.

As he expanded his neural net through his command base, information came at him so fast, reality slowed.

He could see Datarider in the command centre through five new optics. Security cameras. Heard the conversations. Microphones.

And that was just the surface.

Within the network of his command base, Prowl stretched out, reaching into it like slipping a glove onto his phantom limb. His presence soared through ventilation ducts, shifting the flow. He twitched his fingers and Datarider’s console was his — the transmission frequencies shifting faster along with the translations.

He stepped past Smokescreen, staring off through the electroshield dome at Sideswipe holding back the quantum storms breaching his sea.

Where before Prowl could only see the shape of sound in the sand, now there was light. Blue threads of it. Streaking ribbons of calculations. Of the probable states of choice disentangling into waveforms.

Sideswipe knelt to the ground and struck his hands through the chords.

One. Two. Three. Percussive hammered pulses into the ground with the flat of his palm.

Each strike radiated outward in a burst of lit vibration, the sand beneath him rearranging into sharper tessellations — ridges and pits that changed tone with the flow of the wind he stirred.

It was mathematical.

The fine details in the way Sideswipe tiled the ground around himself with shapes of repeating patterns. Triangles, squares, rectangles, circles, irregular shapes — all of them forming from the sand, clicking into a larger design. A larger calculation.

A mosaic of sacred geometry, with no overlap or gaps as their structures ran into each other.

All this Prowl processed before Sideswipe rose from his crouch, humming now — a low bass the piece within Prowl’s spark felt attuned to answering. He didn’t know how to respond, so it was Sideswipe alone whose frame vibrated with harmonic feedback, armor shifting to reveal glowing transformation seams that fluctuated with each reverb.

As Sideswipe raised his hands, material matter of their planet seemed to listen. The air beneath the approaching funnels all flickered with strings of copper light geometry, twisting in the opposite direction.

Counter-funnels expanded from the ground, born from chaos and raised up with practiced skill.

Sideswipe’s natural control over his pitch was remarkable. His confidence in his calculations, a presence itself within his power.

His fingers splayed and shaped along magnetic field lines, modulating frequency and the spin of electrons in the air around him with his every step and vent. A second tone joined his harmony — higher, dissonant — feedback shrieking as his counter-tornadoes whipped forward, slamming into their mirrored counterparts.

The collisions detonated midair.

Perfect implosions. Dust and lightning and thunder swallowed in a flash of collapsing pressure.

The sand at Sideswipe’s pedes reconfigured as he shifted his left leg forward in an arc — mandala-like whorls blooming from the stirring of the sand, branching into a chaos of glimmering constellations. Each new design fed the next, propagating like living algorithms, every spec of twinkling sand an inverted mirrored reflection of staring up at the night sky, and dipping a hand along the surface of the waveforms born of deep time.

“He tunes each tornado funnel’s harmonic signature against itself,” Prowl said, unable to keep the patterns of awe rippling out from him and into the base.

“He… sure,” Smokescreen blinked, and shifted uncomfortably from his gaze the moment Prowl shifted his optics toward him. “If you say. I think it would make more sense to me to see him actually jump up and kick it or something.”

“He’s using the atmospheric pressure zones and magnetic field lines as a carrier medium,” Prowl said, turning his focus back to watching the way the sand formed nested spirals like copper spark frequencies of Sideswipe’s resonance in motion. “Frequencies layered into opposing phase envelopes on the subatomic waveform level. The tornados cancel each other out.”

“That’s… science?”

“So far removed from what we know, it might as well be magic,” Prowl said, because even though he was beginning to see how the equations worked, that was far from him being able to perform them himself without accidentally setting off a ripple effect through waveforms he did not mean to strum.

Smokescreen shifted again, then leaned in and whispered, “Are you meaning to speak out of the base’s speakers without moving your mouth? Because that and your left optic staring through me is kind of freaking me out.”

Prowl had been aware of it, but he hadn’t been aware of how unsettling it might leave those under his command. Networked as he was, it had just felt natural to do. He did not however, know what Smokescreen meant about his left optic.

“Apologies,” Prowl said, using his vocalizer to form the word. “What has changed about my left optic?”

“It’s red,” Smokescreen said, a tightness to his grin. He hesitated in a fraction of a second that felt lifetimes to Prowl before placing his hand on Prowl’s shoulder. “Just don’t go forgetting about the lives of us mortals, huh? Any response from the city?”

“None,” Prowl said as a fourth funnel dragging along the mountain dropped — massive with jagged saw-toothed spirals as if the frequency of Sunstreaker’s compressed rage was bleeding into it. “I suspect Sideswipe’s twin is cancelling out the transmissions to keep the waveforms from reaching her.”

Which meant, Prowl could signal to him directly. Taunt him into coming out and tossing Sideswipe back in. So he did.

The tornado surged toward Sideswipe with supernatural speed.

He didn’t move.

Until the moment the funnel screamed past him overhead, skipping over him — then he leapt — the air crackling behind him as his electromagnetic field blew wide.

Resonate frequencies colliding, oscillations spiking into destructive interference.

A waveform plucked from the sound of war itself, fragmented with static, percussion, and screaming harmonics that felt like they weren’t meant to be heard by the living.

A pillar of sound erupted beneath him, flinging sand into spiral patterns as he launched skyward.

From below, it looked like he was leaping on updrafts, the wind igniting in a grillwork of flowing fractals — heat-mapped patterns of shifting geometry that pulsed in time with Sideswipe’s rhythm and movements.

The boundary of comprehension between science and sorcery collapsed in Prowl’s analysis.

He… couldn’t understand this.

This was far beyond what Prowl could try to cram into his helm.

This was eons of practice and knowledge, that Sideswipe, a split-spark, was naturally inclined toward, with the knowledge of a fully intact, battle hardened quantum-computing, portal-creating, deep space transport-hub Titan behind him.

A terrifying and awe-inspiring force of destruction in his own right.

Sideswipe wasn’t just trained to be an accompaniment of war at Stormsinger’s side: Praxus had had Sideswipe and his twin sparked to be an instrument of his vision’s design. They had been raised and trained by the Council of Speakers as an offering to be placed and weighed upon an alter.

A perfect symbiosis between Speaker and Titan.

Stormsinger, due to the complex nature of her calculations that tore holes in the fabric of reality, burned through the minds of anything less than harmonious.

In the sky, Sideswipe twisted midair, kicking off a pressure front, and released one final pulse from his outstretched hand.

The fourth tornado tore itself apart — shattered by an unseen harmonic that reverberated through every particle of charged air.

Sideswipe landed hard. The sky hissed, the next line of funnels retreating. The winds fell still.

Silence followed, stretching out over the expansive sea.

Only the fractal glow in the sand remained beneath Sideswipe, slowly fading.

With a grimace, Sideswipe sank to one knee as it gave out beneath him. His vents flared as his fans whirred and skipped sand-grit through them.

As Smokescreen let out a loud whoop of victory, Sideswipe looked over his shoulder at Prowl — optics flaring wide in alarm, taking in the sight of Prowl’s mismatched optics, then his entire face lit up.

“What did you do to me?” Prowl asked, voice booming from the speakers of his base again.

Because it was the only explanation Prowl had.

The sliver of Praxus inside him — that Prowl had had to forever guard against for his sanity — was stable.

It was no longer a fight. No sudden stabs of pain behind his optic. He didn’t have to look away from tracking more objects than he ever had before. It felt a part of him, now, his phantom limb found, welded and integrated back properly into his systems.

“A gift,” Sideswipe said, grinning back at him. “Perfectly crafted for Praxus: one he seems keen on receiving.”

Behind him, clouds reformed over the sea, a living wall of rust. Tornados, one after the other, stretched down like fingers — no, like legs — far too many legs.

Legs… the size of skyscrapers, cushioned by tornados.

Cushioned to hold her weight as she shifted in and out of phase. Holding the rift in reality.

Smokescreens cheers died. And so did Sideswipe’s smile.

Prowl sent a transmission to taunt Sunstreaker further.

The city glitched forward, legs bound by tornados skittering across the landscape disturbingly fast. The sky split — tore. Clouds shredded into spirals as lightning carved a rift down the mountainside. A white-hot bolt slammed a few lengths away from Sideswipe, shattering the tile patterns he was reforming.

And in the silence between flash and thunderous roar, he appeared.

Sunstreaker.

Pristine in heavy armor, his armor glowing in flashes of gold amid the yellow of his uranium oxide fire, seared in a smoldering storm-black of decay. Steam curled from him as if he had stepped through a veil, every line of his body etched in radiant charge, as though lighting had sculpted him from a pure, unadulterated cosmos.

A god breaking orbit, entering their realm.

He hovered above a crater still steaming from his descent, not deigning to touch the ground — as if merely touching this material existence he had shut himself away from would contaminate him. The storm bent around him, winds pulled into his gravity, the thunder of his arrival finally cracking through the air in his wake. His presence was the awe-encompassing, terrifying pressure of a gravity well.

He glared at Prowl. Enraged red optics encased in the shadowed-line beneath his helm, his expression cast in iron. An executioner stepping onto the stage of the condemned.

Prowl’s taunting message had clearly been received.

As Sunstreaker hovered there, his electromagnetic field crackling around him in a sphere of his power, Sideswipe rose, and Prowl’s throat constricted in on itself as his calculations restarted. They weren’t… Prowl thought for certain Sunstreaker would have appeared, and immediately tossed Sideswipe back inside the rift.

Sideswipe said they never left their city at the same time.

That they couldn’t, because they’d lose their tether to their city within the rift.

But that had been true even before the rift. Prowl had seen it in the memory Sideswipe shared with him. The two of them never fought outside of Stormsinger together. Unlike other City Speakers, they took turns stepping in and out of their Titan through her portals. Never once fighting the Quintessons beside each other.

Why?

Why, even before the rift, had the Split-Speakers never left their city together? Why not even once on the Quintesson home world, had they not embraced each other beyond their city’s crystalline halls after they were reunited?

That question had barely finished forming an answer in a terrible realization, and Prowl couldn’t dwell on it: he knew Sunstreaker’s weakness. He knew what threat would hold him in place. He could bring Sunstreaker to heel. Make Sunstreaker hesitate long enough that Prowl could ask his questions, without immediately getting gutted.

No words were exchanged between the twins before Sideswipe took off in a flash of light, stalked closely by his twin.

The clouds burst and reknit in flashes and doppler screams of sound — two figures darting through thunder and cloud, faster than computation. They shot like twin comets crashing through fog, their silhouettes flickering in sync with the storm’s rhythm. Weaving through it as probable waveforms, impossible to observe.

Prowl tried to track them.

Failed.

He knew how to bring Sunstreaker to heel — but how could he counter something like this to get a lock on him? They were stepping in and out of their city. Teleporting in flashes that made it seem like they rode on lightning. One pede still there, grounded to Stormsinger and the rift, while throwing a punch, then switching places.

They could leave together, and not immediately lose her. Sunstreaker had just proven that. But for how long?

Prowl couldn’t predict where they would appear next for a targeting solution. The calculations Sideswipe was capable of — his twin was capable of — the nature of them and their city —

Prowl had felt it in the merge. They were more than one mech could contain.

More than one mech could contain.

Prowl turned, pulling his own hardline cable from his neck, extending it.

“I need you,” he said to Smokescreen. “Network with me.”

Smokescreen stared at the hardline cable Prowl held out like it was a living death rising from the depths of their shared past, here to finally sink in its fangs and hollow him out too. He hadn’t had to watch their batch-mates sink into insanity — hadn’t watched them rip off their limbs and try to use them from other rooms, hadn’t heard their screams as they tore through their sensory networks —

But he had been there still waiting, when Prowl was the only one who had walked out of the facility again: barely functional, overwhelmed by every sight and sound, and staring straight through him.

“I can’t,” Smokescreen said. “I’m glitched. I failed the risk assessment, and you got top scores. I didn’t even get in the door —”

“Because you don’t play the odds for calculated risks: you gamble with them.” The cable pressed into Smokescreen’s hands and Prowl closed his fingers around it. “That’s what I need,” Prowl consciously shifted to using his vocalizer for him. “That’s what I lack to predict them as a single entity: an element of chaos to cover my back.”

Smokescreen swallowed, an impossibly long time in only a few seconds.

“They are not demi-gods,” Prowl said. “They are bots like us, but they are, on a spark level, fundamentally quantum beings that exist both in a state of a constant spark merge, and not.” It was a gross over simplification, but it served his purpose of a motivational speech. “They are simultaneously both depending on how we perceive them. I can predict Sunstreaker’s vengeance, but chaos is the flow of their natural state. They know me. If I calculate the targeting solution they’ll predict me, and change the outcome before I perceive them, and get the target lock.”

Flashes of ground bridges lit up the air all around them as Smokescreen’s hand tightened around the cable.

“You are my chaos particle, Smokescreen.” Prowl said. “You drew me back out of myself after my install. You took me on those ridiculous fender-benders to introduce me to the increasing stimulation of variables in my environment. You gambled on what I needed when no one else did.”

Smokescreen squeezed his optics shut and nodded once, then took a deep vent and opened his optics.

“If you think I can do it: a gamble it is then,” he said, doorwings held tight as he lined up the cable on his neck’s socket. “One wild spin of the wheel on the edge of the Rust Sea and see where we land, Commander.”

He plugged in, and Prowl absorbed Smokescreen’s capabilities as an extension of his own. An emergency hardware and software patch to his and logical Praxus’ biggest blindspot.

They didn’t speak with words or feelings, only raw data and code. Prowl could sense Smokescreen in his head analyzing the fragment of Praxus’ readout. His calculations. Where Prowl chose the odds that had the best stable success rate when combined with risk analysis, Smokescreen scanned the solutions for what “felt like” his biggest pay out.

High risk. High reward.

A reckless gamble with their lives.

With the excess capabilities of Smokescreen’s analysis, Prowl’s perceptions snapped the progression of time to flow even slower. Partial tracking. Trajectories.

Lightning crept across the sky like a fissure forming slowly across a frozen crystal landscape.

Among the clouds, silhouettes like giants illuminated in flashes of light. One clawed. One open-handed. Movements mirrored. But inverted. One reaching. One pushing. Creating new storm patterns that thundered through the very mountain tops with each collision.

An opening. Smokescreen placed his bet.

On a statistical probable future, a path Prowl never would have taken alone.

Connected through the base, Prowl oscillated the power of his command post’s shield. Flickering it. Making it seem like it was losing power.

Like he was losing power.

As predicted, the moment of perceived weakness wasn’t ignored. A bolt of lightning snaked toward his location, licking ignited ions through the air — Sunstreaker, calculations blinded by his vengeance and fury, had taken the bait.

In reaction to him, so too, had Sideswipe.

Time snapped back into motion.

Sideswipe flashed into place in front of Prowl, using his body to take the lightning strike that should have torn Prowl apart. He staggered, armor scorched in electric burns, melted in places, glowing red along his seams.

Still, he grinned over his shoulder. That stupid, incandescent grin aimed at Prowl. And a wink —

Then a fist, stained black in decay and trailing in molten gold, punched through the shield-dome and into Sideswipe’s chest.

A wet, tearing crack drowned out the thunder. Prowl’s spark lurched as flecks of glowing energon splattered across his face. Sideswipe’s grin broke into a cough, a glowing, fading pink spitting from his mouth as he arched: impaled and twitching.

Sunstreaker stepped through after his arm, the shield hissing around him, as inconvenient to him as fog. His grip tightened, buried to the forearm inside his twin’s chest.

He smirked at Prowl, gloating in victory, his claws curling around his own brother’s spark.

“I have a targeting solution on you,” Prowl’s voice boomed out of the speakers of his command, the weapons on the base charged and locked. “You’re immortal — unless I kill you both at the same time, then your city will be lost to the rift for eternity.”

At first, there was only a vacuumed silence as Sunstreaker’s smirk dropped, the charge in the air around him rearing back.

Then, the socket in Smokescreen’s neck sizzled and popped — sparks spitting from his seams like firecrackers as Smokescreen convulsed.

He jerked, Prowl’s hardline cable to him tugging free as all strength bleed from him.

Smokescreen crumpled to his knees.

From every angle of Prowl’s camera feeds along the landing platform, the sight multiplied in a kaleidoscopic horror: his single surviving batch-mate hunching over, optics dimming to black.

A wisp of smoke trailing out of his helm in a thin tendril as an offering to the storms of chaos. His doorwings falling limp.

And Prowl felt nothing. No stages of grief. Just the sudden subtraction of him. A hole in his predictions where Smokescreen had always been. A constant variable, held now in a suspended state of superposition.

Both dead and alive.

Until Prowl had defused the now growling bomb of pressurized rage he had goaded then imprisoned in a targeting solution.

Until he could afford the emotional distraction to check.

Chapter Text

A deep ominous bass rumbled out of Sunstreaker’s chest — more creature than mech, glaring at Prowl through the harsh, shadowed-line beneath his helm.

He raised Sideswipe higher, a marionette wrapped around his fingertips, a clear display of ownership.

Prowl’s targeting solution tracked the rise.

“I have a question for you,” Prowl said, unflinching, as a hot spray of energon was coughed out of Sideswipe, and onto Prowl’s face. “Apologies for the theatrics but this was the only way I could get your attention, and keep you from gutting me at the same time.”

His words sounded detached, even to his own audials — his anguished grief for the ambiguity of Smokescreen’s fate, nothing more than another dataset waiting its turn in his overburdened queue.

Sunstreaker, however, vented his fury at being trapped, instead of suppressing it. His hand crushed down on his brother’s spark chamber. Sideswipe’s optics flickered, his frame spasming with uneven charge.

“Sunny — don’t. Please.” Fresh blood bubbled out of his mouth, running down his chin with each word. “I swear I didn’t tell him.”

“Were a thousand deaths not enough for you?” Sunstreaker asked Sideswipe, his burning optics still locked on Prowl, then tracing down the hardline cable that now dangled, lifeless, from Prowl’s neck. “You had to start tempting fate by courting a Praxian parasite?”

If Prowl flinched now — if he thought about the dead weight of the cable against his arm — Smokescreen’s last, desperate spin would be for naught.

“This injury between our Titans has bled long enough,” Prowl’s voice boomed from his base’s exterior speakers. “It needs to be sealed as a greater threat builds on the horizon.” Prowl didn’t know how much time he had left to figure this out before one of the twins needed to return to anchor Stormsinger from within the rift. “I cannot help solve it if I don’t know what caused it. What is a parasitic systems corruption to a Titan?”

Though Sunstreaker’s optics burned into Prowl with the heat of his entire sea, his mind wasn’t on what Prowl was saying. As Sideswipe spoke, pleading, it was clear Sunstreaker was in the middle of a private conversation with his twin through their symbiotic bond.

“I had too,” Sideswipe rasped, his pedes fully leaving the ground as if he weighed nothing to his twin. Meant nothing. His thick, worn fingers scraped and pried at his brother’s forearm, wires crackling and popping free of connections within his chest. “These gummed-up crank-shafts started a planetary war.”

Prowl flinched, mirroring Sunstreaker, as Sideswipe’s sudden vitriol ripped through them in an electromagnetic pulse.

“What?” Sunstreaker snarled, and his murderous glare snapped away from Prowl, landing on his twin. “When?”

Sideswipe choked in a wheezing, gurgled gasp on his words. “I need the tides… the star charts… to finish recalibrating. They changed… their units of time.”

“Again? Frag it.” Sunstreaker dropped his twin. He shook his hand to the side, flicking droplets of Sideswipe’s fresh blood and static-charge to the sand. “This is why I never want to go out.”

Sideswipe sat where he’d been dropped at Prowl’s pedes, fans on blast and sucking in deep vents, holding his spark chamber in place as his rapid-self repair filled in around it. Neither one of the brothers seemed concerned Prowl still held them in a terminal targeting solution. They argued as though the charged railguns, cannons, and turrets, meant to tear through airborne assaults, were background static.

“But even you have to agree,” Sideswipe said, fans blasting while holding in his healing internals, “A planetary war, after everything she’s sacrificed… for Praxus’ vision… we can’t ignore —”

“Parasites,” Sunstreaker said, flicking his fingers to dispel more of Sideswipe’s blood. “Let them consume each other. Let them shatter into dust. Let them fall to rust.” His words were an incantation sung into a curse. He stuck out his hand, still slick with Sideswipe’s blood for him to take. “Only us, Sides. We honour our oaths and accept our fate. Symbiosis is who we are. The parasites chose to let their Titans rot in peace.”

He spat ‘chose’ like choice itself was a vile curse.

Sideswipe pulled his hand out of his own chest as his armor began to knit itself closed. He flexed his hand into a fist.

“But —”

“Maybe the next iterations emerging from the ashes will actually be worth the blood we spill for their paradise,” Sunstreaker said, then blew a harsh gust out of his vents. “It's been so boring Cybertron-side since we finally got Megatronus to stay dead.”

“There’s a new one,” Sideswipe said, clasping his hand against his brother’s forearm — the same hand that, just moments ago, held his insides together.

Sunstreaker’s hand tightened on his twin’s forearm in return, and he yanked Sideswipe to standing. “Is he hot?”

Prowl continued to stare, all the weapons of his base fully powered and aimed at them; Smokescreen simultaneously dead and not dead where he had collapsed. A hole subtracted from Prowl’s life. Sideswipe’s blood was still sprayed across Prowl’s bumper and dripping down his face — and that was the first non-terrifying thing Sunstreaker had said since Prowl’d heard him knock on Sideswipe’s ‘door.’ It was almost conversationally normal. Except it was terrifying in a different way that that was Sunstreaker’s first thought.

“Eh,” Sideswipe wiggled his hand, not put off by his brother’s question in the least. “I looked him up for you: could use a transmutation, or two.”

As if that were the reasonable question to ask after learning about a rising warlord trying to plunge Cybertron into an endless planetary war.

“That can be arranged.”

“There’s a new Prime too,” Sideswipe said.

“Who let that happen?” Sunstreaker scowled as he dusted off Sideswipe shoulders. “Don’t they know how hard they are to kill?”

“That’s what I said!”

“Bet it was Iaconus.” He licked his thumb and attacked a scorched smudge on Sideswipe’s cheek. “That massive diva is always scattering relics like a glitter trail with no Speaker to clean up after him.”

“That’s what I thought!”

“It’s like no one appreciates how hard we worked to kill the last one,” Sunstreaker pulled a cloth from subspace, tilting Sideswipe’s chin to wipe the blood from his face. “The Quints always find a way to corrupt them through Primus. Ugh. Don’t they know I have better things to do than add another one of their tacky paint palettes to my garden?”

“I know! It’s so rude!” Sideswipe said, optics a bright blue-green, grinning as his twin’s began to soften to match. “And Vos is out there hemorrhaging without a Speaker, there’s a rumor going around they have a seeker who can tele —”

Both the twins’ heads snapped back toward their sea in unison.

“She’s drifting,” Sunstreaker said at the same time Sideswipe said, “I’ve got her.”

In a flash of blinding light Sideswipe was gone — only the acrid scent of ozone and burnt copper wafting from where he had stood…

And Prowl was left standing there with only one-half of the mortal pair still snared in his net.

The payout from his and Smokescreen’s gamble had gone sour; the chips he’d stacked to his advantage swept from the table before he claimed them. He’d fixated too long, trying to dissect Sunstreaker’s twisted sense of honour and ethics — enthralled with the change in him. The brothers gossiped with the casual cruelty of players who knew the house was in their corner: the deck always stacked in their favour. In that hesitation, Prowl had been counted out of the game — the house always wins — his place as an equal among them had been stripped away.

He despised hesitating. Part of him wondered if Praxus had been involved in not letting Prowl take the shot that would trap the Titan’s love — at first terrifying cosmic horror sight — forever in the rift.

Oddly, instead of that thought unnerving him, it comforted him — the idea he’d been overruled within his own head — more than admitting to himself that he still could not pull the trigger on Sideswipe.

And all that Sideswipe loved, while Prowl still had a gaping subtraction held in superposition in his own permutations for the future.

Targeting solution useless with only one of the twins in his net, Prowl coped by fixating on the practical and reprioritizing his queue. He could not stop Sunstreaker if he wished to reduce Prowl to sand, so he turned to check Smokescreen’s status. Pressed a hand to his neck. Warm.

His fingertips dipped beneath Smokescreen’s collarfaring, and he held his vents.

A spark pulse.

He exhaled. Smokescreen would likely suffer some memory corruption, but his core systems were still functional. It was enough to add Smokescreen back into Prowl’s life as a constant variable. He clung to it, pressing his hand harder against the spark-line to keep feeling the pulse. Relief surged through him, then ebbed, pulling back from the flood Prowl’d held behind a dam he feared would soon crack under pressure.

But his movement reminded Sunstreaker he wasn’t alone. He turned, all softness he had when interacting with Sideswipe, erased.

With Smokescreen restored as a constant, Prowl found himself suddenly less apathetic about having his face sand-blasted off. Blast doors slammed shut and sealed as Prowl, still linked, locked down his base. He issued an order for all his soldiers to remain as they were. To not come outside no matter what they heard, until the storms passed.

Sunstreaker didn’t move toward Prowl.

He stood, a backlit silhouette, with the outline of him rimmed by the green of the shield. Still as a sculpted statue. His helm tilted down and glaring, the target lock between them reversed.

“Praxus,” Sunstreaker said, drawing out the Titan’s name in a hiss through his exposed fangs while fixating on Prowl’s red optic. “Black and white, with only accents of red. How uninspired.” His lip curled as he slowly dragged his scorn over Prowl’s frame. “I suppose it fits the monotone of your fragmented existence within this one.”

His focus shifted from Prowl’s red optic to his blue.

“What’s that hideous face on your chest supposed to mean?” He tilted his head, optics drifting in and out of focus. “Autobot. Sideswipe says you called me a god of war — seems to hope that will make me like you.”

He rolled his optics, barely a pause between his sentences.

“He’s also trying to bargain with me not to kill you,” Sunstreaker continued, “and is currently offering to do all my chores mopping up the Quints that smear across our city when they try to squeeze through to re-enslave you all. You from a cult?”

Sunstreaker sounded more bored than enraged now, but Prowl knew better. The rage was always there, compressed below the surface. It was probably insulting to keep Sunstreaker in the target lock, but it made Prowl feel better. It was comforting to fixate on the probability that he could get multiple good shots in that would core through Sunstreaker’s helm and spark — before the City Speaker gutted him.

“I called you a demi-god, actually,” Prowl said, flicking his doorwings. “And no. I’m not particularly fond of religion.”

“Cults are annoying to burn out of a population.” Sunstreaker said, like culling whole swathes Cybertron’s populace was a topic under his purview. “I do not let their influence take root in my city. Do you worship your new Prime?”

“He is the Autobots’ military and spiritual leader,” Prowl said, diplomatically.

“But not yours.”

Too obvious a diplomatic side-step, apparently. Prowl triple-checked that he had control of all the microphones and cameras on his base before he responded honestly.

“The Autobots are a means to an end for me,” Prowl said, straightening and linking his hands behind his back, at parade rest. “My priority is in stopping this war before it grows beyond critical mass and becomes a perpetual motion of ruin and revenge, protecting Praxus, and restoring a lasting peace to Cybertron.”

“How very tactical of you,” Sunstreaker said, and it seemed almost a compliment as he flicked his focus to Prowl’s red optic and back. “If I squint, I can almost see what Sideswipe finds appealing.”

So, Sunstreaker valued Prowl’s candor, and the parts of Prowl that others often found repugnant. Prowl could use that.

“Your brother is as remarkable as he is infuriating. I would invite you in and pour you a drink,” Prowl did not gesture toward any of his doors, and had zero intention of inviting Sunstreaker inside. “But, I shattered my best crystalware before dawn this morning, when I learned Sideswipe spark-merged with me under false pretenses, and stole my command codes from my memory files.”

That got a tug upward at the corner of Sunstreaker’s mouth, as Prowl had calculated it likely would.

He was careful not to use units of time that may frustrate Sunstreaker. Now that Prowl had been made aware of the disconnect from the brother’s gossip session, Praxus categorized how Sideswipe had always said “cycle” instead of “day.” When Prowl asked how many hours were in a cycle, the spliced Titan in his neural net returned no context. Likely then, the Titan’s fragment only knew the time scale Prowl did, soldered together as they were.

“If Praxus had formally called you as his City Speaker,” the hint of a smirk on Sunstreaker’s face lifted higher, “you’d already know an invitation is wasted on me.”

A sudden cold draft blew through Prowl’s connection to the base. Then Sunstreaker’s voice came from within Prowl’s head.

“I’m perfectly capable of inviting myself in.”

Prowl’s HUD flickered to white as the base’s network was ripped out of his control. The external defense system swung to point at Prowl. His joints locked at the same time Prowl tried to rip the hardline and power cables from himself. Fear raced through him in a corrosive boil. He wasn’t crashing — Sunstreaker was in Prowl’s motor controls, idly twisting the strings of code around his fingers.

Prowl’s vision returned, and Sunstreaker let him retain access to the base’s cameras.

It was obvious Sunstreaker had slipped inside Prowl through the hardline cable still linking him to the base. But even inside him, Sunstreaker’s presence was almost invisible. The Yellow Split-Speaker spread through code like a drop of rust: a stain that spread, impossible to contain. His corrosive presence cycled through every system, the larger mass of him disappearing deeper, leaving only stillness where there should be ripples.

Sunstreaker sighed as he walked closer, an executioner bored with the routine. He stopped to loom over Prowl. So close, heat radiated from between the Speaker’s seams.

“Dumb move donning a crown of your own little city around a City Speaker,” Sunstreaker said.

A faint crackle of static charge bled across the thin gap separating Sunstreaker’s chest armor — that was so painfully identical to Sideswipe’s — from physically touching Prowl’s bumper.

The back of Sunstreaker’s sharpened, claw-tipped finger ghosted along the side of Prowl’s neck before gliding beneath the data cable hanging there, the one still linking Prowl to his base.

“I don’t need a cable as a crutch,” Sunstreaker said, from within Prowl’s head.

“A skill imbalance is to be expected,” Prowl used his vocalizer, treading lightly at the surface of the base’s code. “Mistakes are inevitable. You’ve had an eternity to practice. I discovered the truth about the fragment of Praxus in my head shortly before you tried to —”

A single pluck along Prowl’s neural net, and he lost control of his communications centre.

So, Prowl began folding parts of his neural net into Praxus, not just leaning on his predictions for calm but for camouflage — dulling his own separate presence in the code. He calculated the city’s fragment might mask him.

The last thing Prowl wanted was to be pulled under by Sunstreaker, drown in the base, with parts of his consciousness cut off from his frame — which Praxus unnervingly predicted was a high probability. But, Praxus also seemed to calculate this conversation was going ‘well.’

After all, Prowl was still alive.

Once vital parts of his neural net were obscured by the fragment of the Titan, Prowl worked on recalling his stretched phantom limbs back from his base, reeling them in through the currents. Slowly, so as not to draw Sunstreaker’s attention in an accidental lure.

“You’re an interesting little thing,” A faint smile formed on Sunstreaker’s face. “I’m beginning to understand Sideswipe’s infatuation.”

A pit formed in Prowl’s fuel tank, the bottom dropping out as a claw tipped Prowl’s chin up. Sunstreaker stared down into Prowl’s optics.

“How many pieces of Praxus have been destroyed? Forty-six, perhaps more you are unaware of.”

A cold, shivering dread spread from Prowl’s spark. The number lodged in it like shrapnel. Prowl hadn’t answered that — he knew he hadn’t. Sunstreaker had read the answer from Prowl’s neural net, or… was he speaking to the fragment of Praxus?

Both possibilities coiled Prowl’s spark in a defensive ball.

More clever than Praxus’ last Speaker, but that’s hardly a compliment, is it?”

As Sunstreaker rose from the deep, he let Prowl feel the currents stirring around him. Sunstreaker circled, tighter with each pass, before he darted in to rake his claws across the threads of equations entangling Prowl to Praxus — then vanished without any turbulence.

“After all, neither he, or the Speaker of Vos ever figured out they needed to kill us both at the same time. You figured that out in what? A sixteenth of a cycle? While dangling from a string of Praxus.”

Externally, Sunstreaker stared down at Prowl a moment longer, tipping his chin back and forth in the stormlight, before he found an angle he liked for his new carving. His hand raised, a tip of his sharpened claw resting beneath Prowl’s red optic — then he scraped a gouge in an arc, curving over Prowl’s cheek.

“You wanted to talk: so let’s talk.”

He handed the reins of Prowl’s external communications, back over to him.

“The Speakers of Vos and Praxus, they tried to kill you?” Prowl risked agitating more code, moving faster back into himself.

“They did,” Sunstreaker said, a current of code stirring as he slowly rose for another pass, raking teeth and claws — Prowl’s HUD skipped in lines of multi-coloured distortion. It is said, a split-spark cannot live without the other. And they were too afraid of the risk missing while trying to kill me.”

“They got it backward,” Prowl said, Sunstreaker’s claim of a thousand deaths rattled through him. “They tried to kill Sideswipe to kill you, and he lived. Again. And again. And again.”

“They got it backward, and they killed Sideswipe. Again. And again. And again.” Sunstreaker echoed in Prowl’s mind, before switching to his vocalizer, forming the words as if he needed the wind to carry the weight of his accusation. “Sideswipe died here, under your protection, five times. I counted. I always count.”

“He betrayed my trust,” Prowl said, defending his orders to his soldiers. “Compromised and undermined my command.”

“A bold pride-choked excuse to make to my face,” Sunstreaker spat, carving his design deeper into Prowl’s face. “Especially after knowing the fate of Praxus’ last Speaker for trying the same, then sending a message to my city, daring me to come try it with you.”

“I didn’t make it a sixth.” Prowl’s optics flared, lighting the angles of Sunstreaker’s sculpted face in blue and red. “And we both know Sideswipe would have let me — just as he lets you rip out his spark from time to time as your little relief valve.”

A cable on Sunstreaker’s neck twitched as he clenched his jaw. Another animalistic revving growl rumbled from Sunstreaker’s engine.

“He gave you an escape route to protect you from me,” Sunstreaker snarled as he slashed his claw across Prowl’s face in an upward arc. “And you didn’t take it, knowing full well what I’m capable of without remorse or hesitation. Why?”

“I need to heal the injury between our Titans,” Prowl said, sucking in a hiss from the sudden sting of blood dripping down his face from the deep, carving slice. “She would make a powerful ally in stopping this war, and Praxus is not all of himself within me.”

Sunstreaker made another carving cut, but Prowl didn’t spit out the blood dripping over his mouth and mingling with Sideswipe’s. He let it run. Drip.

“I am no fool,” Prowl said, his glare on Sunstreaker unflinching. “I know Praxus is not an innocent party in his Speaker’s actions against you. What I don’t know is why. We reached a frustrating impasse. To solve it, he has been insisting — annoyingly — that you will tell me the truth where Sideswipe lies. That you, of all mechs, are honourable.”

“The truth?” Sunstreaker’s optics burned brighter. “The truth is Praxus is choking on the future he let happen.” He sliced down from the corner of Prowl’s optic. “He gave his last Speaker the freedom to choose his own fate, and that freedom bred ruin.”

The focus in Sunstreaker’s optics went internal then, the touch of his thumb across the fresh carvings on Prowl’s face, suddenly soft as he wiped at the blood. Smearing it.

“Sideswipe has been nothing but loyal to our calling since we were sparked, and he lived a thousand deaths at the Speaker of Vos’ hands because Praxus looked the other way from his wandering out of bounds.”

He yanked Prowl’s head back by his helm’s crest; enraged optics zeroing in on him.

“He allowed his hands and optics to wander,” spit flew from Sunstreaker’s mouth, accompanying his rage, speckling across Prowl’s face, “because he mistook neglect of his garden in peace, for mercy.”

The information spun in Prowl’s helm, and through the thin slice of Praxus, as if he was bludgeoned with it. Variables swam, disordered, then clicking into a frightening, clear picture.

“You loved him,” Prowl said, the personal savagery profile of the murderer behind that cave massacre testified to it. “But he didn’t love you.”

He should have watched his mouth with his conclusion, but he was so stunned — Sunstreaker’s optics turned an apocalyptic hue of red.

“Do not confuse me with my twin,” Disgusted, Sunstreaker recoiled from touching Prowl, releasing his grip. “I do not do anything as pathetic and mortal as fall in love.”

He retrieved his polishing cloth from subspace, wiping at his hand as if touching Prowl had contaminated him. He revved his engine again, neck cables flexing, jaw clenched tight.

“Do you have any understanding how many of Praxus’ Speakers Sideswipe and I have outlived?” He asked, then folded his polishing cloth back into his subspace. “You’re all just a new set of tires to me: fun to break in and take for a spin, but eventually the tread wears thin.”

Yet, the truth simmered and hissed beneath his denial. Prowl could feel it in the echoes of Sunstreaker’s rage from when he turned on him during the merge, and tried to drown him.

Prowl didn’t know what he found more revolting: Sunstreaker’s entitled, invasive touch within him, or to have it confirmed Sideswipe and Sunstreaker had been sent to be intimate with Praxus’ Speakers, whenever their Titans desired that form of physical coupling. One, that without their symbiotic connection, was otherwise denied to a Titan’s existence. That the City Speakers were their cities’ optics, audials, voices — and touch.

Their connection to their people.

To each other.

And Praxus’ last City Speaker hadn’t loved either twin. His spark rotated and yearned for the Speaker of Vos’. That Sunstreaker saw that as a hideous corruption of their duties curdled like acid poured into the energon in Prowl’s tank.

“Vos and Praxus’ Speakers,” Prowl said, “they just wanted their own lives. Their own desires. To be free in their autonomy on the most basic level — not slaves —”

“We are no slaves!” Sunstreaker roared, hands knotted in fists, an electromagnetic whip cracking through the air.

“They wanted a choice!” Prowl roared right back.

Words that echoed out of the speakers, overlaying and overpowering Sunstreaker’s control blocking Prowl from them.

Sunstreaker’s glare shifted from Prowl’s blue optic to his red, his engine snarling.

“And look at the fate ‘choice’ has given to every other Titan but me and mine.” He seethed heat from his vents, fangs flashing in the light. “All their Speakers abandoned their liberators. Their saviors. Their gods. Choice is not symbiosis. It’s corruption. A parasite leeching within the system. Symbiosis in retrograde.” Sunstreaker lashed out, grabbing Prowl’s chin in an iron grip sparking with static, the sting of his touch crackling beneath Prowl’s armor. “It breeds parasites,” Sunstreaker spat. “And I do not let parasites near my Titan. I rip their rotten limbs off.”

“Sideswipe —”

A dangerous pressure wave built behind Prowl from within, and there was no escaping it — Sunstreaker surfaced, slicing red-hot claws into Prowl’s code.

“I rip parasites off my twin, as well,” Sunstreaker hissed. “Sideswipe is enamored to have found a loophole in you.” The claws sank deeper, and Prowl’s doorwings spasmed from the sudden burst of uneven charge coursing through his systems. “That’s all you are: a loophole in our vow. Big enough for a parasite to wiggle through. A hole I can close — if you burn out from this little piece of Praxus in your head.”

A wad of static choked Prowl from answering, and Sunstreaker’s optics flashed again. He pet his thumb across the design he’d carved on Prowl’s face, his voice soft and distant again.

“Sideswipe has gone and fallen in love with you,” he said, then both is voice and the light in his optics hardened. “And you are even more the fool to encourage him to temptation by loving him back.”

With that, Sunstreaker slammed the entire weight of himself against Praxus, tearing open a breech that poured beyond its boundaries. Prowl shrieked in agony as his vision shattered, motor controls grasping to move in vain and yank on the back of his helm and rip Sunstreaker’s fist out of his head.

But the hand igniting the quantum connections back to the full, encompassing pressure of the city-Titan, Praxus, wasn’t physical. As Sunstreaker held Prowl’s face against the entirety of Praxus, he poured a molten crown of electromagnetic charge over them. Fusing them.

It burned. He needed to rip it out. Choice. There were too many paths to take. Too many probable futures.

Too many choices.

“What’s wrong Prowl?” Sunstreaker said, taunting, as the crown fusing Prowl to Praxus grew larger and spread in tall, molded spires. “This is what you asked for. This is what you wanted. Wind. Flashes. Fire. Rust. Ruin. The power of a Titan is not yours to command — but a weight you bear.

Prowl’s screams fractured, splitting down the path of every possible future. Most breeding ruin. None devoid of suffering. Peace, no more gentle than war in the sacrifices that had to be made. Not for everyone. Never for everyone.

Is the responsibility of the crown you’ve donned as Praxus’ self-appointed Speaker too heavy for you, Parasi—”

The burning, overwhelming weight of probability and choice was abruptly cut off. And in an instant, control slammed back into Prowl’s frame as Sunstreaker stood there wincing and holding the side of his head like feedback was blasting through him. Prowl didn’t hesitate —

Heat flared over his shoulders as he ignited his mounted missiles point-blank into Sunstreaker — sending him flying backward. Sunstreaker hit the shield in a spray of fire.

Prowl’s entire frame heaved as he drew heavy vents. His hands clenching in an out of fists, molten code still dripping down his spine to cool between his doorwings as he watched the smoke begin to part.

Sunstreaker, already mostly healed, lurched to a knee, the light in his optics flickering through their spectrum, one hand still clutching his helm. Prowl’s blaster flipped into his hand — then Smokescreen was standing in front of Prowl, unsteady on his pedes, his hands frantically checking Prowl over, wincing at the damage carved on the one side of his face.

… Smokescreen… Prowl’s chaos particle. The data and power cables that had been linking Prowl to the base — Sunstreaker’s gateway into him — they dangled in Smokescreen’s hand.

Even as Prowl processed how Smokescreen had intervened, he was leveling his blaster at Sunstreaker.

“Smokescreen: Run,” Prowl ordered, his weapon hot and warping the air as he charged it to maximum.

He would shoot Sunstreaker — and he would keep shooting Sunstreaker. A thousand deaths. An eternity. If he had too, Prowl would stand here shooting him for eternity.

But Smokescreen didn’t run, he checked the damage to Prowl’s face over again, then — to Prowl’s slow-motion processing horror — Smokescreen walked up to Sunstreaker and flared his doorwings. He tilted his head at the golden monster of the Rust Sea — who glared straight through him, flickering optics struggling to stay focused on Prowl.

Smokescreen looked back, standing in the path of Prowl’s charged and aimed blaster.

“I don’t…” he turned and clapped his hands in a sharp motion toward Sunstreaker, then back to Prowl and said, “I don’t think he can see me.”

“What?” Prowl kept his blaster trained on Sunstreaker, side-stepping Smokescreen from his clear line-of-sight.

Sunstreaker, again, failed to rise: gyros whirred without axis and pneumatic lines hissed then lost pressure. Yet, even as he clutched his helm, he kept trying to watch Prowl. Optics stuttering between furious hues of red and Sideswipe’s calm copper blue-green.

“He keeps staring at you —” Smokescreen said. “He didn’t even see me stumble up to pull the cables out of you. He looks straight through me, like he’s a defense system that doesn’t register me as a threat.”

Prowl’s finger twitched on the trigger, as Sunstreaker got his arm under him, but only by locking his elbow. “How do you know?”

“Because after your tactical network install: that’s how you used to look through me.”

After the piece of Praxus was installed.

With a more critical optic, Prowl watched as Sunstreaker tried to force his limbs to obey. Even after they healed, they buckled beneath him. It was like he was glitching…

Or he couldn’t figure out how to use his limbs.

“I can’t go anywhere beyond the Rust Sea for long, Sideswipe had said during their merge. “It would trap Sunny in the rift, and he’d grow colder. More isolated. Less interested in anyone else but me than he already is.”

There was something deeply wrong with Sunstreaker. Prowl saw it now — an observation he could not have made without Smokescreen, because Sunstreaker very much did see Prowl as a threat.

But he didn’t see Smokescreen. He might as well not even exist.

“There’s nothing wrong with Sunny,” Sideswipe had hissed, turning away from Prowl. “He just gets a little over protective sometimes. I can calm him down.”

This was what Sideswipe was protecting, why he was so desperate to push his boundaries. Why he kept excusing everything Sunstreaker did.

Sunstreaker had drifted so far inward, become so isolated in their caged existence, he was becoming more city-Titan than a mech.

What happened to a City Speaker when they started being absorbed into a city’s consciousness? When they became less of a detachable limb, and more of a permanent fixture within their host?

Terrified of losing his twin and his city after Vos and Praxus’ Speakers tried to kill them, Sunstreaker had overcorrected. Choice was his enemy. He had dedicated himself to simply being an extension of his Titan’s duty and will.

To all, except Sideswipe, Sunstreaker had become more walls than warrior. More of a statue on stand-by. More automated defense system than an autonomous being with a spark and his own desires. He had begun to perceive all others in terms of threat assessments, parasites, or raw materials for the sculptures of his garden — the only interest he seemed to still hold on to that was independent of Sideswipe. The last sliver of self he hadn’t ceded to his Titan.

So, Sideswipe not only forgave the gruesome interest, he encouraged it. Sideswipe had found in Prowl an oasis in his desert sea. Held Prowl in place to let Sunstreaker taste his spark, no matter the risk to Prowl.

Because Sunstreaker saw Prowl. He saw Prowl in fine detail. Every detail, every flaw.

Now, Prowl saw him.

Sunstreaker had never been allowed the luxury of choice. Not once in his entire life.

From the moment of his ignition, he had been trained to be an offering. An instrument of war. To be laid at the alter of his city-Titan’s will.

His fate had been either to succeed as Stormsinger’s City Speaker, or be burned through like all the others who preceded him. And maybe he had been burned through.

Again. And again. And again.

Because Praxus had been cunning, sending an offering to Stormsinger that couldn’t die — not while his twin was kept hidden and safe with the Council of City Speakers on the Quintesson homeworld. Split-Speakers, who could guide Stormsinger’s calculations through a quantum string to the precise location Praxus needed when the time came.

A perfect symbiosis.

Praxus’ design. Their only pathway to freedom. To get Cybertron through the blockade.

Sunstreaker’s fate was a mirror to the prison Prowl found in Sideswipe. Bound together, eternity decided for them, whether either would have ever chosen to spend it together or not, they’d never know. That choice did not exist for them, at the most fundamental privacy layer, they were entangled.

It had been safe to fall in love with Praxus’ Speakers. They could tell themselves it was fated. Destiny. Through the Titans’ symbiosis, Sunstreaker claimed them as his right — his duty, to run his city’s hands all over Praxus, as Sideswipe had once said.

But for Sunstreaker, Praxus’ last Speaker had been love. His love. An unrequited love at a time Praxus began to question if his Speakers should have a choice in the matter, now that Cybertron was formed, and they were at peace.

Except the twins and their Titan had never gotten to settle in peace.

Prowl knew what love felt like to Sideswipe. It was invasive, suffocating, and all consuming. It was their nature to be incredibly intense and insecure outside of themselves with others. From Sunstreaker, the weight of being the focus of his affections must have been unbearable.

Vos’ Speaker had tried killing Sideswipe — one death to end them both, to free Praxus’ Speaker from Sunstreaker’s crushing, possessive obsession.

For the price of Sunstreaker falling in love, Sideswipe had suffered a thousand gruesome deaths — the Titan Vos was split into fragments, the connection to Praxus viciously severed, and Sunstreaker had withdrawn from the planet he sacrificed all his life to create, then guard.

Megatronus may well have been his last personal interest in a mech outside of Sideswipe. And even a corrupted Prime would have been an emotionally safe outlet for his obsessive affections. Stalking him would have only been encouraged. He had had to be killed, but that hadn’t meant he couldn’t play with him first.

In the two most essential parts of life, Sunstreaker had never had a choice. To him, choice had become a contagion — free will an infection he had learned to carve out of himself. He leaned into his fate.

Yet some part of him knew. All that compressed rage, ticking inside him, and with all that power and responsibilities of his crown crushing him…

He was a reactor without a vent.

Without a release valve, he knew one day he’d snap, and nothing could contain the aftermath.

Prowl lowered his weapon, and walked toward him. As he approached, Sunstreaker struggled to stand again — failed and looked painfully confused — as if he’d left his legs in another room and couldn’t remember where. Tormented by the parallels Prowl had watched as his batch-mates suffered, Prowl crouched next to the ticking time-bomb that rarely left the safety of the Rust Sea.

“Sunstreaker.” Prowl’s hand hovered for a spark-rotation before resting it on Sunstreaker’s forearm.

Sunstreaker’s optics scanned the contact, they flickered, but he didn’t detect a threat. He seemed confused by the sudden heat on his arm, and if someone wasn’t going to attack him, or come on to him — why would they want to touch him at all?

Prowl’s spark broke for him a little more. How long had it been since someone other than Sideswipe had touched him?

Since Praxus’ last Speaker, who had recoiled from him and tried so desperately to flee the suffocating weight of Sunstreaker’s love.

The only love he had ever been permitted, the only outlet his fate would grant him, and even that had been controlled by Praxus’ choosing — until Praxus took that away from him too.

“Sunstreaker,” Prowl said again. “Praxus is a Titan who gained self-awareness when he recognized the value of choice within himself. The war for freedom demanded sacrifices, but Cybertron is made. You do not have to be so tightly bound by fate.”

A power surge rose within Prowl, aching to reach out, and uncertain if he was doing it right, Prowl took a deep vent. He gathered the charge Sideswipe had left in him, and hoping Sunstreaker would recognize its frequency, sent it into Sunstreaker, grounding it through him to Cybertron.

Sunstreaker seemed to stabilize in himself. His limbs stopped shaking as if they’d belonged to someone else, at least.

And a solution tore at Prowl, knowing what it would mean for Sideswipe, but Prowl made a choice.

“Your skill is remarkable,” Prowl said, doing his best to wrap his awe of Sunstreaker’s abilities in the twin’s language. “I did not know I was capable of reaching more than just this sliver of Praxus. I require a mentor to teach me how I can connect to him.” He swallowed the static that threatened to crack beneath is words as he thought of Sideswipe. “I propose we start small: establish trade routes between our cities. Rebuild trust. Praxus has a large collection of art galleries that may interest you. And I have a connection to a mech who will see to it you experience the most spectacular fender-benders of your life.”

Sunstreaker shook his head, refusing to look beyond the touch on his arm. “Sideswipe —“

“Wants you to get out more,” Prowl said, confident that was true. “Live. Let Sideswipe do your chores and you can experience the world you safeguard from the external threats, while still performing your duties to your city by teaching me how to connect with Praxus, and to defend Cybertron from within. I am improvising every step as I go, and you have made it very clear I’m making some ‘dumb mistakes.’ I find myself in desperate need of your counsel.”

Sunstreaker was silent for a long while, his optics glazing, focus gone — arguing with Sideswipe in the space between reality only they shared.

When Sunstreaker’s gaze returned, it locked on Prowl’s blue optic, unblinking.

“You are not Praxus’ Speaker,” he pulled his arm away from Prowl’s soft touch as if it burned him. “I will only mentor the one who is called.”

Prowl blinked. “What?”

The polishing cloth returned to Sunstreaker’s hand and he scrubbed at his arm as he rose. Confused, Prowl rose with him.

“This is the shape of the landscape Sideswipe has set in motion,” Sunstreaker said in his native tongue, then switched to formal Praxian. “You are the loophole he has knotted our fates through.” His focus dropped to Prowl’s Autobot insignia, branded over his spark. “Congratulations.”

He didn’t sound excited about it.

“You are mortal,” Prowl said, even knowing Sunstreaker would never admit it. “You care for your city. Her battle with the Quintessions has never ended. She sacrifices still to keep Cybertron safe. How can you turn your back on us, when we call for your aid?”

And Prowl paid for reflecting the truth at him — for holding up a mirror.

“We hold the rift,” Sunstreaker said, refusing the choice Prowl offered him in favour of the familiar bite of fate that was devouring him. “Your Titans allowed themselves to be consumed by choice. Their Speakers all eventually chose to refuse their calling. Not us. Never us. We are a perfect symbiosis of Praxus’ design. It is our fate. We do not flinch from it.”

“You’ve consumed yourselves,” Prowl reached out for Sunstreaker again. “Sideswipe wants — if you just switch places with Sideswipe for a moment, let me talk to him. We can solve this.”

“Forget Sideswipe,” Sunstreaker said, gripping hard on Prowl’s wrist. “Where he is soft, I am unyielding. I accept he has bound us together by fate, but with me on the outside now, my Titan has no cracks for parasites to crawl into.”

“It’s a prison for him,” Prowl said. “He wants trade routes, connection, to help — Sideswipe doesn’t want to stay locked away from the rest of Cybertron, and he doesn’t want that for you.”

“You think I don’t know the spark of my spark, my one and the same?” Sunstreaker hissed, “The winds shaping the landscape of our futures are now forever tied. But that does not absolve Sideswipe of his responsibilities —” his optics narrowed “— you will never see him again, except by my leave.”

He released Prowl and rose to his full height. The winds around him picked up, electromagnetic charge stirring the air. Static crawled up his frame, condensing around his audial fins in a crown of storm and sharpened teeth. Within the dust storm beyond the dome, the shadowed-shape of a large, cylindrical cable stepped through the rift, shaking the ground upon impact.

“I am Stormsinger’s voice,” he said, his tone fracturing into a chorus — three voices braced in perfect harmony. “Titan. Tempest. Guardian of the Rift and the Rust Sea. We speak to you as one mind, and when a city speaks —” the harmonics crashed together, metallic thunder reverberating through the base as the visibility outside the dome was swallowed — “you will listen.”

Sunstreaker’s optics strobed through the full spectrum of copper patina, light flickering across a star-field of waveform dunes.

“You are not Praxus’ Speaker,” Stormsinger said, through Sunstreaker. “When Praxus shows remorse for the ruin his choices have wrought — when he calls a voice for himself again properly — I will answer. Until then, you will have no more dealings with my Split Speakers, distracting them from their calling. You may bleat upon the shores of my sea. We will not answer, until Praxus’ calls.”

The harmonics bled into the wind as it stilled, the storm beyond the dome dying, and Sunstreaker turned away.

He walked through the electroshield dome. It shimmered around him, sparks dancing off his frame. He paused on the other side, hands clenched tight at his sides as he cursed under his vents.

Then he turned back slightly, shadowed optics — a piercing blue-green — that cut back over his shoulder.

“You will live to regret loving my brother, Prowl,” Sunstreaker said to a rhythm — a vow woven of fate and laced in a sacrifice of sorrow. “It’s a curse. One I have never been able to break.”

Prowl stood frozen, Praxus’ read-out blank, as Sunstreaker’s silhouette bled into the dust settling in the air — until there was nothing left but the soft hiss of the rust-sand shifting, erasing the path he walked.

Consumed by the fate binding him to his sea.

Chapter Text

Crystal fragments clinked and clacked across the forest floor as fingers of the chinook winds reached deep into Praxus’ famed Crystal Gardens. The warm, dry currents escaping the Rust Sea blew over the Manganese Mountain range, devouring the chill of frozen condensation settled on their daunting peaks — heralding a change in seasons.

Yet another season passing, where the warm, dry winds teased and tormented along the leading edge sensors of Prowl’s doorwings.

Another season of the wind gently touching his face. Another season of daggers finding Prowl’s spark, with every playful gust that had him looking over his shoulder.

Another season. Without any whisper on the wind from Sideswipe.

The wind still found him, even this deep within the Crystal Garden’s neglected paths. Remnants of the layered harmonics drifted in from the singing Sapphire Cathedral. Here, the crystalline song stretched thin — strung to a wire thread from its cathedral’s ancient growth halls. The wind carried the hallowed melody on warm, seeking tendrils; gusts that sulked through the cracks, whispers that clung to the broken spires then fell stagnant, trapping Prowl with the scent of burnt copper and ozone at the centre of the Dead Grove.

Prowl stood at the base of the towering dark crystal, hands linked behind his back, and staring at his solitary reflection. The suspended arcs of fossilized lightning split his face down the centre, their jagged fractals blending into the scar carved beneath his left optic.

There had been an acid on Sunstreaker’s sharpened fingertip — one unknown to medical science. Prowl assumed Sunstreaker had gathered it from the uncharted territory of the Acid Wastes. Materials he used to shape the deranged corpse statuaries of his garden.

The exact translation of the symbol remained unknown to Prowl, even after all these decades, but its intention was clear: Sunstreaker had branded him — had scrawled what he saw as immutable fate — marking Prowl as separate for all to see.

Trust Sunstreaker to make a scar, a brand of fate, both aesthetically pleasing and quietly menacing. Once healed, it resembled an intentional cosmetic design etched beneath his left optic. Its sharp curves rose and fell like waveforms, terminating as it curled upward at the corner of his optic — a tendril of wind. Sculptural and beautiful, it was a design that had bots in the room shifting nervously whenever Prowl dove into a complex statistical analysis.

The scar glowed red, along with his left optic, any time Prowl’s tactical network previously would have threatened to crash. Prowl had no control over it.

It only deepened the aura of mythos and mystique that had gathered around him as his notoriety grew within the Autobot ranks. A whispered belief that Prowl’s calculations were guided by Primus, or worse — that he’d traded a piece of his spark to the old gods, a deal brokered by the creatures that stalked the Rust Sea.

To the Autobots’ medical team, Prowl became a baffling medical mystery. His neurological map from his recruitment physical had changed, drawing the attention of the Autobot Chief Medical Officer.

Prowl’s neural net had breached his cortex. It now threaded into systems it had no business reaching — clamping down his spine, pooling to a point between his doorwings, then branching in fractals within them.

On the scan, his neural pathways looked as though a crown of lightning had been poured over his head and solidified upside down.

The Autobots’ medical conclusion: exposure to the Rust Sea’s electromagnetic winds during the Hexagon’s breach had altered Prowl’s neural net. He was lucky to be not only alive, but functional.

The magnetic bursts had caused his neural net to absorb his battle computer. It was no longer a device of experimental hardware and software inside his head. It was indistinguishable from Prowl.

It had become Prowl — or Prowl had become it. In the maddening entangled symmetry of the split-twins who ruled the Rust Sea, the answer was probably both.

All Prowl knew was that Sunstreaker had somehow fused him to the shard of Praxus the day the Yellow Speaker connected him to the entirety of the Titan — and held Prowl’s face against the scorching heat of endless probabilities that screamed at how naive he had been. Someone always suffered in peace. All ages, no matter how grand, died in depressions that bled into the next rise. The universe, inevitably, evaporated in a heat death of decay.

Since that day, Praxus had remained silent in Prowl’s head.

The day Prowl had hidden his vital systems within the Titan’s fragment as a shield. The day Stormsinger had declared she would not forgive Praxus until he called a Speaker properly.

The last day Prowl had seen or heard from Sideswipe.

Despite dedicating his every spare moment to scouring records, translation, and those faintest crumbs Sideswipe had left him, Prowl still could not figure out how to be called as Praxus’ City Speaker — ‘properly.’

He failed to see how Stormsinger could not recognize that it was Praxus’ choice to give his Speaker autonomy that had set this entire string of fate into motion — the TacNet Project that led to Prowl requesting an audience at Praxus’ behalf upon her shores, all of it.

“The path the wind takes to shape a future landscape is never direct.” Prowl murmured in Sideswipe’s language, tracing his finger down the jagged line of fossilized lightning cutting through his reflection.

Be patient, Sideswipe had said, thinking in the timeframe of mountains. Time that moved differently when he was with his twin.

Time that left Prowl standing still. Waiting. Wanting. Longing.

Prowl didn’t know what thought was more haunting: that Sunstreaker still had never returned to their Titan-city and Sideswipe remained trapped alone inside her — or that Sunstreaker had returned, and the brothers had spent all this time laughing and joking with each other about the latest gossip Cybertron-side, while mopping up Quintessons.

Forgetting all about Prowl, and any urgency, as they had the day he held them in a terminal target lock on the shores of their sea.

Another playful gust of warm-magnetic wind ghosted over his doorwings. A heavy sigh left his vents. He was incapable of feeling wind as he once had. Now, it was a constant reminder of the touch he didn’t have by his side, always seeping under his armor, no matter how tightly he sealed it. His spark, forever captive to the wind’s slightest touch.

He glared beyond his split reflection in the dark crystal’s facet: no closer today than any day before to fixing it.

A portal to Sideswipe’s city.

The largest crystal in the Dead Grove, with facets facing every direction, ranging from the height of minibots to ones tall and wide enough to accommodate even a shuttle’s passage.

And was it just this crystal that was a portal?

Over the long years, as Vos’ technological escalation only grew in magnitude — a welling bubble of magma threatening to erupt — Prowl had searched every other grove cluster in the Crystal Gardens.

Could he find a portal to Vos and dump a payload through it? Could he find the right resonance to rip seekers from the sky? Could he hardline into Praxus with a large enough power source, and turn the Gardens Stormsinger had sung for him into a weapon?

Like every other time Prowl’d come here on leave, working his questions in his mind, he never got any closer to solving them.

The ability to see the inner workings of Sideswipe’s calculations faded over time. It was a terrible feeling — to have once glimpsed the machinery of a power that should be his, only for Sunstreaker to deny him mentorship under a technicality of an outdated tradition.

Prowl was ready and willing to step into the role of Praxus’ City Speaker. He would enter into the vow optics open. He knew he could handle it — and yet, he’d heard nothing that could be defined as a calling. Even hardlining into Praxus yielded nothing more than practical automated functions beneath the inner workings of a city, as it had for him during his days as an enforcer.

So Prowl had stretched out his phantom limb into growing a network in other ways.

The influence of his power within the Autobots.

He’d gained notoriety — and an award — for predicting and evacuating the Autobots’ Rust Sea outposts before the ‘once-in-a-star’s lifetime event’ of the Hexagon stretching into the Manganese Mountains’ foothills.

The award meant nothing to him, but shaking Optimus Prime’s hand — getting on his radar — had been an opening. One Prowl had built upon.

Whispers had followed, of course. They always did. That the official story, the one Prowl’s remaining soldiers had agreed upon, was not all that it seemed. There were the ones that talked. That Prowl, their base commander, had been compromised. Seduced by a ruststalker’s song. That he’d nearly sacrificed them all to its endless hunger, in exchange for his strange, new power.

Exactly once, Prowl had tried telling the real account to the head of the Autobots’ Science Division. Worse than encountering disbelief — she had accused Prowl of having a ‘fanciful sense of humour.’

After that, he built his own science division within hers.

He sent his network out, and found his own talent. His own quantum physicists and engineers. Wheeljack, in particular, had been a worthwhile investment. Eccentric and brilliant, but without political instinct or drive to climb the ranks — something Prowl had taken upon himself in his own designs to change behind the scenes around the inventor. Prowl had sent Wheeljack everything he could sketch of the crystalline resonance patterns he’d glimpsed: quantum harmonics made manifest in matter.

The calculations for a working ground bridge portal were possible. That was what mattered. It was only a matter of time before Wheeljack and Prowl’s shadow science team solved the equations — and the Autobots would hold a massive tactical advantage.

A small faction of the calculation power of a deep-space transport Titan.

The power to move troops and supplies far behind Decepticon lines.

Prowl’s hand was steady as he continued to trace the path Stormsinger had severed between Praxus’ grove and hers. If she would not recognize that Prowl acted in an underlying harmony of Praxus’ best interests at spark, then he would do as Sunstreaker had — and kick down her door. Invite himself in.

That tenacity was why Sideswipe had chosen him. Prowl was certain of it. After his encounter with the Split-Speakers of the Rust Sea, Prowl had become even more cunning, more subtle in the strings he pulled — more dangerous.

After all, Sideswipe had said: “that’s why this will work. It has to be you.”

Praxus’ City Speaker had to be Prowl.

Sideswipe’s freedom depended on it.

Sideswipe. Prowl’s spark still ached and curdled to think of him. A prisoner of his own city’s calling, and his split-spark nature. Clawing at the cage he couldn’t see, bending the rules and stretching his boundaries, trying everything he could to make Stormsinger see reason, as his twin was devoured inward.

Did Sideswipe stand in this very same place, reflected in his Titan’s mirrored Crystal Garden, staring back through some parallel facet? Was he there even now, longing — with only the weight of Stormsinger’s crown biting into his neural net, and his brother’s tormented statues for company?

He could be with Sideswipe. Help both twins bear the crushing weight of their calling. Mend this rift.

Was it truly a sacrifice of Prowl’s free will to act as Praxus’ hands when Prowl was already willing to run them all over Sideswipe the moment he was called?

And Sunstreaker — Prowl could make good use of him. Coldly. Tactically. In ways that Sunstreaker respected and would benefit them both. Ways that would draw Sideswipe’s brother back from the edge of his transformation. Help him reverse his course.

Less city, more mech.

Prowl stiffened as he picked up a change in the wind behind him. A disturbance, moving around an object that hadn’t been behind him just moments before. A bot. Small. Closing fast.

But no sound. Only an unnatural stillness in the welling pressure wave through the air as the presence came to an abrupt halt.

Prowl dropped his hand from the dark crystal. He didn’t turn. He didn’t need to. He could see the youngling’s reflection in the crystal: wide blue optics, frozen in terror, as if finding a mech standing as a sentinel statue in the Dead Grove was akin to a monster crawling out from beneath his berth.

“Shouldn’t you be processing your educational packets?” Prowl asked, narrowing his optics at the reflection.

The youngling’s plating was clean, yet scuffed in places. His primary colour was a vibrant electric blue, his chevron and accents silver. His doorwings, black and flat against his back, created a contrast that made their movements easier to read — the twitch of uncertainty, the shrinking in on himself, the shake of a matching blue helm.

Uncanny, how much he looked like a miniature clone of Datarider.

When the youngling didn’t answer, Prowl frowned. “You should speak when addressed.”

The youngling’s hands balled into fists, gold joints on his knuckles exposed as he found his courage. Doorwings shot upright in challenge born of pure instinct to not cower from monsters.

“I’m not supposed to talk to strangers,” he said, in perfect, unaccented formal Praxian.

Relief flickered through Prowl’s circuits, to learn the youngling could actually speak. Prowl had heard that development marker had been delayed — had feared he had done something wrong to have caused it.

“You’re not supposed to be in this grove, either,” Prowl linked his hands behind his back as he turned, regarding the youngling directly, careful to keep his aura of command steady — any wavering, any flinch, would start a crack.

Primus, it was so hard to look at him with the turquoise blue of Sideswipe’s patina-bright optics staring back.

“Where are your creators?” Prowl asked.

Small, electric blue shoulders raised in a shrug, framing the sides of his black chestplate, his doorwings slicking back down. “Ditched them.”

Hidden from view behind his back, Prowl clenched his hands until his joints ached, to stifle the trembling of his spark — a trembling he refused to allow to enter his voice. “Do you have weapons installs already?”

“No.”

“Combat training?”

The youngling shifted on his pedes, glancing away from Prowl’s face to the Autobot brand on his chest and back. “… are you trying to recruit me to fight for —”

“No!” Prowl said, more forcefully than he’d meant too. Those small, black doorwings shot up in alarm, so Prowl measured his tone with an explanation. “If you are unarmed, you should not be away from your Creators, as you are still too —”

“BLUESTREAK!”

Prowl’s spark collapsed, crushed in a fist barbed with claws. The tightness shot through him, knocking everything, even his balance, off rhythm. He caught himself taking a reflexive step back. He had assumed they would have given him a new designation — not kept the one… the one Prowl had —

“I don’t need weapons,” Bluestreak said, sticking out his tongue as he pivoted in place and dashed down the path. “My crystal friends keep me safe.”

Prowl regained his footing, doorwings rigid, hand outstretched and lunging to grab him. “Your crystal… what? — Bluestreak, wait —”

But he was gone, small doorwings pulled tight as he slipped through a narrow crack at the base of a dark crystal, running illegally off-trail through the gardens.

Prowl stood, arms dropping limp at his side, staring at that crack as if it were a hole, a seam in reality, that had split open and taken him.

There was only silence, even the wind of the changing seasons dared not to disturb it, until another pressure wave approached.

Heavy pedes clomping up the chipped path through the Dead Grove before a frazzled Datarider came skidding into view.

“Have you seen —” He froze when he saw Prowl standing there, and out of habit, snapped to attention and saluted. “Sir!”

“I told you I don’t want him here.” Prowl returned his hands behind his back as he fixed his glare on Datarider’s yellow optics.

“All due respect, Sir,” Datarider said, grimacing. “You waived your rights to Bluestreak decades ago.”

A cable on the side of Prowl’s neck twitched as he grit his back teeth. “It was my one rule.”

“I might as well be static interference for the number of times I’ve told him he has the rest of the gardens to play in, but he always ends up here.” Datarider shrugged his shoulders like there was nothing he could do to stop the whims of a small bot that only came up to his knees. “I think he likes it because it’s the only place where everyone doesn’t stare.”

“Why would they stare?” Prowl asked, flicking his doorwings. “What’s wrong with him?”

“Nothing,” Datarider bristled, his armor raising. “He’s just a youngling. A sometimes loud, shrieking, chaotic, suddenly quick, normal youngling learning how to move about the world: developing his neural net through trial and error. Bots in Praxus just aren’t used to seeing one.”

“Has he said he’s seen things in the crystals?” Prowl asked. “Heard voices from them, drawn patterns like the sixth-dimensional language in the files —”

“What?” Datarider pulled back, brow furrowing. “No.”

Prowl took a step forward, crowding Datarider’s space. “Then why, after I warned him it wasn’t safe to run off from his creators without combat training or weapons installed, did he tell me his crystal friends keep him safe?”

“Crystal friends?” Datarider repeated, then laughed. “He means his refracted reflections. He chases them through the gardens, playing hide and seek.”

Prowl narrowed his optics. “Should he not be playing with his real friends?”

That was a thing younglings did, wasn’t it? Prowl was certain he’d read it was important for the development of their fine motor and social skills. Then again, he’d deleted all those files in a fit of rage and despair.

“He doesn’t have any,” Datarider said.

“No friends?” Prowl scowled.

“Don’t give me that look,” Datarider said, snapping in his youngling’s defense. “Nothing’s wrong with him. Primus, Commander, you really have no idea how hard it is for him do you?”

Datarider paced back and forth, pressing his fingers against the base of his silver chevron.

“And me,” Datarider continued. “The looks I get for having a youngling under the threat of planetary war — as if I am the one being selfish and irresponsible with resources.” He tossed up his hands, spinning to face Prowl. “A sparkling doesn’t just happen if both parties of the spark merge don’t put energy into it! What else is anyone going to think? The creation of one is an intentional act — they don’t just happen by accident!”

Prowl’s knuckles creaked further under strain, and Datarider seemed to realized what he’d just said as the scar carved into Prowl’s face flared a scathing red.

“I didn’t mean to imply that — Sir,” he stammered, trying to recover. “I don’t doubt your account. The things that happened out there — it’s just…” He gestured over his own chest, where his Autobot insignia was once branded over his spark. “How did you not know?”

“I will include a bonus at the end of the month.” Mask of iron back in place, Prowl brushed past him. “You will use it to fly him in a friend twice a month. There is a service bots in the Towers District use to socialize their vanity blanks. I’ll send you the pamphlet.”

Prowl kept an even pace as he followed the uneven bricked, neglected path that led out of the Dead Grove — not running, proud his doorwings didn’t sink as the warm, dry wind curved along their edges, a mockery of Sideswipe’s touch.

It was easier to blame the wind — blowing over the mountains from the Rust Sea — for his foul mood. Its very nature was to come and go, without respect to the marks it left torn through the future landscape it shaped.

Prowl slammed the applications onto the desk, glare cutting into the Autobots’ Chief Medical Officer.

“You will not approve any of these,” he said, each word clipped enough to cut diamond.

Ratchet leaned forward in his chair, and scanned the forms in the pile of datapads. His brow raised beneath his helm. “Why do you have copies of these?”

Catching the cracks before they split him wide open, Prowl forced himself into neutrality. His posture shifted to professional, non-defensive, his arms not crossed, but at his sides.

“None of these applicants are qualified.” He could not stop his left optic from burning hotter with every word, or the way his brand flared.

“Again,” Ratchet’s expression hardened along with his tone. “What business is it of Tactics to access, let alone read, adoption applications?”

“It’s a safety risk,” Prowl said, internally proud at how steady he kept his doorwings. “You have bots applying from everywhere within the Autobot territories for —”

A jolt of static coursed through Prowl’s frame, his words dying as a small, overly warm hand slithered into his. He lost control of his composure. His spark clenched tight, doorwings flaring. The air behind him hadn’t even shifted — and yet, that small, warm, tentative weight was there, holding onto him. A solid fact. Prowl couldn’t look. To look would be to make the improbability real, to give it a face.

A colour.

A co-ordinate.

He couldn’t.

Ratchet rose, his expression stunned and freezing mid-vent. Prowl focused on that — anything but the presence beside him. Throat constricting, Prowl managed to form words that didn’t crackle.

“Once again, Bluestreak,” Prowl said, still not daring to look, “I find you sneaking into areas restricted to you. Return to your recovery room.”

Chastened, the little hand in his almost withdrew, but didn’t. Prowl was so focused on not looking beside himself, he had to replay Ratchet’s next words — realizing his grave error.

“Bluestreak?” The Autobot CMO walked around his desk and crouched in front of the small youngling with his fingers still loosely linked around Prowl’s hand. “Is that your name, brave little one?”

They hadn’t had a name for him.

All anyone had known was he was the only survivor — the single flicker left from Praxus’ total annihilation.

Prowl hadn’t realized they had no identification. Had assumed his name had been omitted from the adoption applications for privacy reasons. He hadn’t realized there had never been one.

But of course they hadn’t had a name, Bluestreak had no production stamps. His ID code would have been lost in Starscream’s malware attack that ripped through Praxus’ systems.

Bluestreak was a blank.

He’d been in shock. And hadn’t said a word.

Prowl should have known. Should have seen.

But he’d been too busy dissecting the ruins of his city — his Titan — examining the angle of every crumbled building, every shattered crystal, reverse engineering the crime scene. He had been consumed in trying to understand how his calculations had been so wrong. How the seekers had gutted Praxus so thoroughly, as if they had torn a portal through the Crystal Gardens, and set the Titan on fire from within.

Sideswipe’s plan was supposed to side-step the threat of Starscream entirely.

Static rang in Prowl’s audials. Through it, he heard Ratchet’s questioning get even more invasive.

“Bluestreak, do you know this grouchy mech?” Ratchet asked.

The hand in Prowl’s clasped tighter, and Bluestreak ducked behind Prowl’s leg as if suddenly shy. Bluestreak nodded. Prowl could feel it in the way the air shifted beneath his doorwings.

He should have sent Smokescreen here with the forms. As one of the few remaining Praxians on all of Cybertron, Prowl should have made Smokescreen apply.

Stealing himself to deal with this without crashing emotionally, Prowl tried to not make it obvious how hard he wanted to seethe and grit his teeth — his carefully engineered promotion to the head of the Autobots Strategic and Tactical Division, under threat.

“Use your words, Bluestreak,” Prowl said. “I know you can.”

Prowl braced for Bluestreak to say something ridiculous and damning to Ratchet like: ‘this mech tried to recruit me in the Dead Grove —’

But what Bluestreak actually said was even worse than Prowl’s predicted worst case scenario.

“He sent my creator money to buy me a friend.”

Prowl winced, a full-bodied jerk that almost had him ripping his hand from the youngling’s disturbingly warm grip threading beneath his armor.

And Bluestreak kept going.

“My friend’s name is Hound. They bought him from Kaon, but the forms said he was from Kalis. He told me the truth because I’m his friend, and he says he likes visiting me because Iacon stinks like too much glitter and perfume.” Bluestreak sniffed twice. “But I don’t smell it.”

“Is that so?” Ratchet said. Bluestreak flinched from the glare the CMO sent Prowl’s way, so Ratchet softened his tone. “Why did this mech want to buy you a friend?”

“It’s a service the bots in the Towers District use for their vanity blanks,” Bluestreak answered, his words identical to the ones Prowl’s used, as if his mind was a trap that recorded everything meant to damn him. “He was worried there was something wrong with me because I didn’t have any friends that weren’t crystals. But you keep checking me over, and saying I’m fine — remarkable, not even a scratch.”

“I think,” Ratchet said, glancing meaningfully from Bluestreak, to Prowl, to the adoption applications on his desk, and back. “Prowl and I have a lot to talk about.”

“Don’t make him leave!” Violent eddies stirred the air as Bluestreak’s doorwings flapped wildly in distress. He clung tighter, even went so far as to wrap his other overly warm, sticky hand against Prowl’s forearm. “He’s scary, and makes the screaming stop.”

Visions of blue-ribboned streaks of light weaving beneath his armor during the spark merge collided with the heat seeping through his seams.

Prowl blinked, as Sideswipe’s words were dragged out from deep storage, handing him the unique resonance he’d ignited in a crystal shard.

“This is one we need to save Praxus. And all of Cybertron. Something for you to hold on to: like you asked.”

As Prowl’s carefully crafted world — a world that revolved around himself at the centre of the design — began to crack, he finally looked down.

The mirror image of Sideswipe’s optics stared back. Pleading with him to stay — by sending a manipulative frequency through him that tugged at his spark’s crystal chamber.

Bluestreak’s optics were still turquoise, but when compared to the last time Prowl saw him, the edges of them were starting to bleed more green, with a faint ring of copper, not yet gone to rust.

Prowl wanted to tell Bluestreak he wasn’t that scary, but the words would not form. It was a lie, locked in his vocalizer. Terror lanced through him along with the realization of what that colour shift in Bluestreak’s optics meant. For seconds that felt like a glimpse of eternity down a completely new pathway he’d overlooked, Prowl simply stared at the single survivor of Praxus’ obliteration.

The survivor, who had been found wandering in the remains of the Crystal Garden, without so much as a scratch.

“Whose screaming do I make stop?” Prowl asked, his emotions buried behind his carefully constructed mask of control.

“Everyone’s,” Bluestreak whispered, burying his face against Prowl’s arm, muffling his words. “I hear everyone burning alive. Their fuel lines igniting. I could see them all. Crushed as they ran terrified through my crystal friend’s veins. He was screaming too — screaming at me to run and hide, to call my creator from the Dead Grove. Except my creator was with me, trying to get a signal out to you, but the Seekers were swarming out of the Sapphire Cathedral. And… they killed him — they tried to kill me, and him, and us — there were so many, swarming like parasites, and I…“ his vents came in rapid gasps, doorwings flailing wildly. “I...”

He dropped to an inaudible whisper, shaking amid his rapid vents.

“What did you do, Bluestreak?” Prowl asked, numb.

“I just wanted the pain to stop,” Bluestreak said, shaking his head, vents heaving as he smeared his tears against Prowl’s arm. “Don’t leave. Please. Creator said I’d be safe with you.”

Creator.

Prowl knew Bluestreak meant Datarider, but all Prowl could think of was Sideswipe.

“This is one we need to save Praxus. And all of Cybertron. Something for you to hold on to: like you asked.”

All at once, Prowl’s careful predictions — his logic, his belief in patterns of observations — imploded, shards as sharp and damning as the shattered remains of the Crystal Gardens.

He had spent decades trying to crack the calculus, to find a path to reach Praxus through his fragment inside him, to be called as his Speaker — properly.

He had thought Bluestreak was an accident. A complication born of Prowl’s inexperience with matters of the spark.

A complication that could jeopardize everything from Prowl’s rank, to his ability to route forces to defend Praxus without Praxus entering the war.

Sideswipe —

Sideswipe had kissed his spark chamber after the merge. Had placed his hand over Prowl’s spark before he left and told him he’d already given him everything needed to save Praxus. For peace.

He knew.

And Sunstreaker had looked right at the Autobot insignia over Prowl’s spark and gave a begrudging: ‘congratulations.’

There was no future for them in which Prowl had been meant to be Praxus’ new Speaker. He was the loophole. There was never going to be a grand reunion between their cities with Prowl at the centre where he and Sideswipe —

How could he be so foolish? Blinded by his own ego, capabilities, and calculated potential of what he could become —

Sideswipe had left Prowl sparked on purpose.

He had used Prowl as a vessel.

A mold, to forge Praxus the thing Sideswipe thought Praxus needed most: a new City Speaker. One he and Sunstreaker wouldn’t be sent to be intimate with. One Stormsinger and Praxus could see as a manifestation of their love in a different way. One Sideswipe could use to ground Sunstreaker to Cybertron by having him be called as his mentor.

A gift.

Sideswipe had said he’d left Prowl with a gift for Praxus. He’d had been so elated with his solution in which he could get to keep Prowl — his loophole — all to himself, he was incapable of seeing the difference between a gift left for Praxus was a theft from Prowl.

His autonomy. His choice. Set on the alter of fate.

A fate given to this youngling Sideswipe had left his “dangerous and clever” Prowl to protect and prepare for his destiny.

And Prowl, consumed by his own designs, by the traumatic revelation of what the TacNet Project had truly been, still reeling from Sunstreaker’s invasive and entitled touch — had been unable to handle even looking at the sparkling once it came out of him.

Let alone think much about him without drowning the feelings he couldn’t handle, and his longing to free Sideswipe, into his work.

His life’s purpose. His destiny of his own forging — he was in charge of his own fate.

Protect Praxus. Protect Cybertron.

Now, Praxus was dead.

The only sliver of him remaining, integrated into Prowl’s neural network — flaring awake because Bluestreak was anxious, traumatized, and hemorrhaging his power. It was everywhere, swirling all around them, invisible. Only Prowl recognized its touch. Bluestreak didn’t know what he was doing, but he was trying to influence Prowl into staying.

Prowl’s presence calmed him. And it wasn’t because of some special bond because Prowl had carried him.

Bluestreak could subconsciously sense the resonance of that little piece of Praxus, but he had no idea what it was.

What he was.

What he had done.

“This is one we need to save Praxus. And all of Cybertron. Something for you to hold on to: like you asked.”

As Prowl tightened his grip on Bluestreak’s trembling hand, holding onto him, he made a vow.

He would not let Bluestreak be strangled by the same fate that choked his creator and kept him chained.

No one — least of all Bluestreak — would ever know the truth.

That, in trying to defend Praxus, called as his new City Speaker — panicked and untrained because Prowl had taught him nothing of what Sideswipe had showed him, had not brought him to the Rust Sea for Sunstreaker to mentor —

With no foundation to understand what he was doing as the Seekers of Vos shrieked through the portal they opened within the Sapphire Cathedral, killing the only creator Bluestreak knew in front of him —

Bluestreak had tapped into the resonant power of his crystal friend’s veins to save him.

Only to destroy him.

Destroy everything.

And everyone.

To make the pain stop.

Chapter Text

They looked like empties.

The hanger bay beside the Medical Centre, high in the spires of Iacon, should never be this quiet. The air up here was thin, normally chilled, dry, and sharp with the altitude. The usual relentless wind, gusting in from the outdoor platforms of the open hanger bay doors, was subdued. It was as if even the wind knew not to disturb what was left of the returning scouting unit’s sanity.

It instantly set Prowl on edge. The unit Prowl had come up here to debrief had the vacant look of soldiers who’d faced a horror outside of comprehension.

In the back of his processor, he filed Ratchet running scans and First Aid shining lights into optics and visors. Some responded to stimulus. Some didn’t. Others tracked Prowl’s straight-line procession to their transport.

The majority of the scout unit did not register as individuals to Prowl. He recognized them all as specific sets of skills he had hand selected for how they fit together as complimentary puzzle pieces to perform his objectives. Only two waiting outside of the transport were distinct to Prowl as individuals.

Hound, a rugged scout attuned to harsh terrain, and of even temperament, had a gash along one side of his paint-abraded helm and he was missing an arm — but the majority of Prowl’s processing power was locked on Bluestreak.

And the jagged fractal burn pattern scorched into his armor like a silver inlay.

It started at the tip of his left black door wing and arced over his shoulder, down his chestplate, and jetted inward, cutting through his Autobot insignia — stopping just short of reaching his spark.

Prowl’s internals roiled in acid, denial racing through him even as he reached for his emergency protocols — pinging Jazz a wordless tone pattern to standby.

Jazz responded in a solitary ping, indicating he was already on his way.

But Hound was also here. Bluestreak was here. Why were they here? Everyone in Prowl’s shadow organization within Spec Ops had the same orders. None of them knew the others’ safe houses. Whoever was closest to Bluestreak was supposed to disappear with him.

Surrounding Bluestreak in a network of highly trained guards — one of them always nearby — it was the only way Prowl could start letting Bluestreak out of his sight after his final upgrade, without raising Bluestreak’s suspicion.

They were all genuinely Bluestreak’s friends. Or Prowl’s.

Prowl had just repurposed them. Refined them. Honed their edges. Pulled the strings to close them into shield against the danger hunting Bluestreak’s very existence.

Letting Bluestreak live as normal a life as possible was Prowl’s goal. As normal as anyone could get anymore in the midst of a planetary war that showed no pathways to resolution.

Prowl could not predict the time or manner of Sideswipe or Sunstreaker’s arrival. He could not guess the day they’d raise their heads from themselves and wonder: shouldn’t Praxus have a new Speaker by now?

“Sides,” Prowl could hear the probability of Sunstreaker asking one day, as he poked his head out of his garden. “Where’s your creation? The one meant to save Praxus?”

Now, Bluestreak had come back from a scouting mission dusted in rust-sands and marked by lightning; his, and everyone else’s, shoulder-mounted munitions spent; his entire unit looking as if they’d peered between the cracks of the universe — and found something monstrous staring back.

Why hadn’t Hound followed the protocol surrounding Bluestreak?

What had gone wrong?

It had just been a routine scouting mission. They weren’t meant to be anywhere near the Rust Sea.

Yet, every soldier of Bluestreak’s unit had been kissed by a fine dusting of rust. All of them. None had had the presence of mind to wipe it off during their transited return to Iacon.

But Bluestreak was whole. Alive. And here.

If Sunstreaker knew what Bluestreak had accidentally done with his powers as a City Speaker, and found him, the probability that Bluestreak would still be alive was low.

He wouldn’t be here.

Bluestreak was still here.

Prowl fixated on that as a lifeline.

As Prowl approached, he read the subtle hand signal from Hound indicating: ‘All Clear.’

But Prowl couldn’t release the anxiety gripping his spark that only got worse as Hound began to give his report.

“Sir, we were chased across the Lithium Plains and pinned down a few leagues from the uncharted territory of the Acid Wastes,” he said. “Our reinforcements were taken out. No air cover. The only way out was the slot canyons and risk the acid tides, or over the white silica dunes by Magnesium Ridge.” He paused, swallowing, then shook his helm. “Seekers were circling — too many for Blue to pick off before they had our position. They corralled us into a canyon, then started dropping in on an attack run.”

Bluestreak picked up the thread, staring down at lighting strike that cut through the Autobot brand on his chest, his doorwings already cycling in anxiety. “That’s when the screaming started.”

Prowl tensed, energon rising to his audials in a dull roar, “Screaming?”

“Yeah,” Bluestreak shuddered, then hunched further in on himself. “Carried on the wind as the colour of the sky turned inside out. The canyon walls shook. It… it sounded like a monster.”

“What did?” Prowl asked, fearing the answer he already knew.

“The rust storm,” Hound said as Bluestreak nodded. “It —”

“It ripped over the canyon — over us,” Bluestreak looked up, optics flaring in a halo of copper at the rim, cutting Hound off. “We thought we were dead. Like Primus Himself had opened a gate through the mountains to the Rust Sea and had sent the storm tides to flow over us, then grab and drag us out.”

“And then?” Prowl asked, voice and doorwings even, fingers curling tight around his datapad.

“The storm stood on the canyon walls over us, reaching out,” Bluestreak said. “And ripped the Seekers out of the sky.”

“You mean the storm overwhelmed them?” Prowl asked, carefully, but could not keep his brand from flaring red.

The soldiers who still had the presence of mind to be able to listen flinched, suddenly looking away, finding a spot on the floor very interesting.

But Prowl didn’t dare take his optics off of Bluestreak. Or the way the halo gradient in Bluestreak’s optics had gotten wider; more reddish-brown at the edges.

Bluestreak frowned, his doorwings slicking down, a flicker of betrayal forming behind his optics at what he assumed was Prowl’s disbelief of his account.

“The storm stood, hovering on the canyon walls — tornados tearing into it like drills laying anchors — and it reached out,” he repeated, not backing down from what he’d seen, no matter how illogical he thought Prowl would find it. “I’m not being poetic. There were cables — shadowy spindles — massive, as huge as skyscrapers — bigger than skyscrapers even. They just grabbed the Seekers like they were insignificant bugs. We didn’t even hear or see explosions. Just… gone. Swallowed by the rust in the howling wind.”

Prowl’s spark rhythm fluctuated as the painful memories swirled to the forefront of his mind in crystal clarity. He flicked a doorwing to dispel the touch of a warm teasing wind seeping along his sensors.

The screen of the datapad in Prowl’s grip distorted in multi-coloured, oil-slick hues.

Sideswipe had been so smug after their merge. Had been so insistent Prowl leave. Had taken Sunstreaker’s hand after he had tried to kill Prowl and the new spark barely clinging to life — after he had punched through Sideswipe’s own chest to rip out his spark, and then joked about whether or not Megatron was hot —

And left.

A gift, Sideswipe had said.

For Praxus.

A curse, Sunstreaker had said.

For Prowl.

That’s what Prowl had gotten out of loving Sideswipe. For getting to know him. For wanting to shelter him. Free them both from their tormented fate Praxus’ design had caged them in. An outlet. A pressure release. A chance for them to enjoy the world and the freedom they helped create and guard.

Sunstreaker had tried to warn Prowl, too late, what it meant to have his life entangled with theirs.

Prowl refocused onto Bluestreak, on the lightning-track fractals burnt into his plating, as his tank turned itself inside out.

Everything. The secrets. The truth Prowl kept from Bluestreak, wrapped in comforting lies — it was all going to turn to rust no matter what Prowl did, wasn’t it?

They knew. They knew Bluestreak had been in danger. Stormsinger must have felt Bluestreak hemorrhaging the waveforms of his power through the silica dunes at the edge of their range as he ran. Heard his panic for his friends and fury for the Seekers on the wind.

Why didn’t they take him? Why hadn’t Sunstreaker killed him? Did they not know about Praxus?

“Did you see anyone?” Prowl asked.

His question, after his unnaturally long pause, cut through the ranks. They rippled as a liquid, disbelief transmitting through them like a contagion. They wanted Prowl to be the sane one. To take his glitched creation — who had probably not shut up about what they all saw the entire ride back — to the Medbay, so they could all convince themselves they hadn’t seen what they thought they had.

A monstrous city, within the storm.

They were willing to ignore it.

As Prowl should have done a long time ago: ignored Sideswipe and his seductive songs of mystery, control, and power. Whispers of a future that had only left Prowl twisted and decayed inside.

He should have done what the old stories said: simply turned and walked away.

What was it Sunstreaker had said? Sideswipe’s attention was a fleeting thing. If Prowl had ignored him, Sideswipe might have gotten bored of him and left. Instead, Prowl had encouraged him.

Now, he had unleashed them. Created a tether back to Cybertron for them to care about.

Ruin and rust would follow their steps. He had spent the long decades taking precautions, building protocols, searching the old stories, tracking down relics, but he couldn’t hope to control them when they came. Just distract and redirect them.

Long enough for Bluestreak to be hidden away.

“I didn’t see anyone,” Hound said, slowly. “Just dust. Static. Shadows. Sand.”

Bluestreak shrugged, hesitating like he shouldn’t say, but he always ran his mouth when nervous, especially under Prowl’s stare. “It felt like someone heavy knocked into me as a missile was heading at me, but it could have been anybody in my unit as we scattered… and there was a bright flash but no thunder — except I have this mark, so it must have been lightning that knocked me across the canyon, right?”

It wasn’t. Prowl knew it. Either Sideswipe or Sunstreaker had been in that storm, stepping through a ground bridge and singing Stormsinger’s path up that canyon.

Fuck.

They definitely knew.

Prowl pinched the bridge of his nose and closed his optics to hide how his left one was flaring red.

It was too soon. Prowl needed more time to try to explain things to Bluestreak. He had told him the old stories when he was little, yes. The legends and the myths to prime him for this day. Bluestreak still thought of Datarider as his creator, but he knew the one who’d ignited him had been an unaligned mech Prowl’d met in the Manganese Mountains during his first command. He still struggled with panic attacks and power flares even though Prowl had had his memory files of Praxus’ destruction suppressed by Ratchet to help manage them at a functional level —

Bluestreak was a fully-developed adult mech now. He should be allowed to choose, but Prowl could not ignore the probability that Sunstreaker was going to kill him as a corrupted Speaker and —

Fuck.

There was never going to be enough time to explain to Bluestreak what he’d done. What he was… had been. To Praxus. To the future that could have been. The one lost to them now.

If Sideswipe had told Prowl he’d planned to fix Prowl’s predictions by passing on his legacy of being used by Praxus as a means to an end — by placing another youngling on the alter of fate to solve their problems — Prowl would have refused to spark merge with him, and told him he was being a gummed up crank-shaft.

But submitting himself to the winds of fate was all Sideswipe knew.

Another playful gust of wind tormented Prowl’s doorwing’s leading edge and he flicked them, hard. Remotely, he closed the hanger bay doors to shut out the annoying breeze. The hanger locked down, causing the techs to jump, uncertain where the command had come from. A harsh, frustrated vent blew out of Prowl’s entire frame’s cooling network as he ground his teeth.

“What were the coordinates?” he asked, still pinching the bridge of his nose to hide how he was keeping his hand in front of his left optic while glaring out the right.

Hound shared an uneasy glance with Bluestreak at the intensity of Prowl’s optic flaring red beneath his hand. Prowl descended deep into his analysis of contingencies he’d prepared, superimposing the coordinates Hound rattled off onto a map.

His vents caught mid-cycle.

Stormsinger was on the other side of the Manganese Mountains? Far outside her perimetre. Farther than she’d ever walked before.

How had she even fit through a mountain pass while still holding the rift? That would have been agony on her legs.

A burst of fleeting laughter, rumbling like distant thunder rolled into Prowl’s audials, and he shook his head, trying to shake the thrall he still had over him free.

“We… uh,” Bluestreak rubbed at the back of his neck, doorwings shifting in rapid succession, uncomfortable and anxious, as he always was when Prowl’s dual coloured optics bored into him, while not seeing him. “We did pick up a stray at the evac zone as we were taking off. No ID, but Smokescreen vouched for him. Said you and he go way back to your first command?”

A delay in Prowl’s processing was no longer common. Neither was a crash. Only one infuriating mech could manage to make Prowl’s neural net stall so completely. He blinked at the cautiously curious expression on Bluestreak’s face —

A chill filled Prowl’s entire frame.

No. Smokescreen wouldn’t. He knew the protocols. He, more than anyone, knew how dangerous —

A second round of rolling thunderous laughter rang through the hanger on the tailwind of another teasing breeze — even though the hanger doors were now shut — and Prowl whipped in the direction Bluestreak glanced.

“WHAT?” The word surged out of him.

And there he was.

That impossible, irresponsible, rust-sucker Sideswipe.

He sat with his back to Prowl, on a supply crate, gesturing wildly with both arms and laughing while Smokescreen listened with a half-worried smile. His plating was just as rugged and scuffed as ever, paint dulled and worn thin at the edges from the abrasive sand and debris swirling around his ever wandering city.

He had the nerve to look and sound exactly the same, as if time and any worry or consequence had passed him by.

Prowl shoved his datapad at Bluestreak, then stalked across the hanger bay, a vengeful, simmering storm in his own right. Smokescreen saw his thunderous approach, his doorwings going ram-rod straight.

“It’s not my fault,” Smokescreen said, privately over comms. “I couldn’t just say no to the guy who can spawn tornados when he’s asking for a lift — he showed up as we were taking off.”

Prowl’s fury increased tenfold. Sideswipe could hear the comm traffic. That was exactly why the protocol surrounding Bluestreak was sign language and pings.

Sideswipe glanced over his shoulder, blue-green optics catching the light like tumbled, polished glass from the shores of his sea.

Grinned. Waved.

And winked.

“You’re welcome!” He called, overly loud so everyone on this side of the hanger could hear. “Sunny wanted to kill everyone else in the canyon along with the seekers, but I recognized my favourite back up singer Smokeshow here and was like ‘hey, those are Prowl’s fingers out there,’” he elbowed Smokescreen in the side, “— and you remember how much I love when he fingers along my shore —” his gaze dragged along the lines of Prowl’s frame, his engine purring in approval at the changes, “All it took was an easy cheat on the coin toss, and —”

Prowl’s fist collided with Sideswipe’s stupid, smug face, a force so powerful in his upgraded alt-mode, he toppled Sideswipe off his perch, sprawling him out across the floor.

Sideswipe blinked, resetting his optics. Then pressed his hands to the floor and flipped onto his pedes, rubbing at his jaw. He had the nerve to look at Prowl like he was confused. “Not quite the gentle, eager touch of the little zephyr I remember —”

He caught Prowl’s next swing, his grin straining at the edges as his hand closed in like a vice around Prowl’s fist.

“I told you, I don’t get time off —”

Prowl spun to sweep out Sideswipe’s legs in a kick while signing to Hound to get Bluestreak out of here — but Sideswipe didn’t let go, or have the decency to fall. He twisted with the motion, placing his hand on the narrow of Prowl’s waist as he held firm to his coiled fist. As one, they swept through a series of steps that felt alarmingly like a dance until Prowl was spun and trapped in Sideswipe’s arms, doorwings pinned against his broad chest.

At the same time, Prowl wirelessly reached out and took control of the hanger’s defense systems. All the turrets in the room snapped to attention, laser target locked in on Sideswipe.

A deep rumble left Sideswipe’s engine, vibrating through Prowl’s delicate sensors, as he laughed.

“What are you going to do with that? Shoot me and piss Sunny off more?” A teasing breeze trailed across Prowl’s neck as Sideswipe leaned in, brushing warm lips across his audial rim. “I’ve missed you as the tide longs for the shore. Each retreat a clawing agony. Every return, roaring back to crash against you.”

A burst of traitorous charge bloomed beneath Prowl’s armor. Licking along his crystal spark chamber as Sideswipe’s lyrical language flooded into him — trying to simulate his emotional communication that came so easily between him and his twin.

”The charge of my spark.” Sideswipe nipped along Prowl’s neck cable, sending a shiver of more charge through him. “I’m never as warm as when you are near.”

He pointedly pressed his heated pelvis against the top of Prowl’s aft, unconcerned to have an audience.

“Release me, Sideswipe,” Prowl ordered through clenched teeth.

“Too late for that, Love,” Sideswipe whispered, and a heatwave slipped beneath Prowl’s pelvic armor as a gust of wind traced beneath his bumper. Wiggled the latch, teasing. “Our fates are bound.”

He raised his helm, looking pointedly across the hanger bay at where Bluestreak was digging in his heels, gawking in shock as Hound was trying to effectively drag him away with only one arm. And it wasn’t just Bluestreak — Ratchet had his hands over his mouth, alternating between looking at Bluestreak and his creators and back.

Jazz’s visor was flashing as he used his hands to slide down on the railing of the catwalk steps, positioning himself to intercept if Bluestreak got separated from Hound. Prowl sent him a flicker of a ping in gratitude, and to stand-by.

“Praxus is gone,” Prowl said, and it had been decades more, but saying it still stabbed.

“Not all of him,” Sideswipe’s arms constricted tighter, holding Prowl in a shared grief that Sideswipe had no right to understand. “That’s why I’m here.”

“A little late,” Prowl said, his vocalizer snapping in static. “Don’t you think?”

“Zephyr —”

“Do not start with me —”

“Prowl —”

“I am the Chief Tactical Officer of the Autobots —” Prowl hissed, an audible hum of the hanger bay’s weapons charging to punctuate all around them. “This very public display of affection is unbecoming of a mech of my authority and station.”

“Well, good for you —” Sideswipe said, letting him go only to spin Prowl under his arm to face him. He started dusting off Prowl’s shoulders, cupping his face, drinking in the sight of him like he’d been starving on empty. “I have no idea what that means, but it sounds very important —”

“It means I am in the Prime’s High Command,” Prowl snapped, knocking Sideswipe’s hands from him and turning away.

He glanced at Hound’s progress out of the corner of his optic, as he started leading Sideswipe away. Prowl sent a separate ping, relieved to learn Mirage was somewhere in the room with his relic on standby.

“Oh,” Sideswipe said, before jogging to catch up. He darted in front of Prowl, walking backward. “Well, good for you.” He leaned forward, dropping into his language again. “The wind could take him —” he switched to formal Praxian. “Well, not for free, it’s not easy to take out a —“

Prowl’s doorwings flared high, blocking Sideswipe’s view. “Don’t you dare —”

“Just saying, if you want that final promotion, just let me know.” Sideswipe glanced around Prowl’s doorwings, across the hanger, perking up. “Those are pretty fancy.” He was looking at Hound — or more accurately, the hard-light holograms of Hound. “You make these?”

By now they were scattered through the landing platform, as well as detailed copies of Bluestreak, moving in all directions.

“This is great,” Sideswipe said, taking a step around Prowl into the thick of them. “The details down to the sparks coming out of the missing arm… ” he whistled. “Sunny’s going to be so impressed.”

Oh no, did he think Bluestreak made them?

“Where you from?” Sideswipe said, stepping in the way of one of the holograms of Hound, poking it in the centre of its helm. “You’ve got amazing talent and a keen optic for detail.”

“He’s from Kaon,” Prowl said, grabbing Sideswipe’s arm and turning him back toward him.

“Kaon, huh?” Sideswipe said, rising on the tips of his pedes and glancing back to look over his shoulder. “Guess the borders have bled more than I thought. That’s good though, it was the Quintessons that sorted everyone by type, you should be branching out.”

Then Sideswipe reached out, hummed and flicked a hologram they passed on its nose.

It shattered. In a chain-reaction, all the holograms spreading out through the hanger bay shattered.

Hound was left exposed, hand digging into Bluestreaks arm, Bluestreak still arguing with him and looking back at Sideswipe — shocked.

Sideswipe grinned at Prowl, caressed down the side of his face with the back of his hand. “I don’t think I ever mentioned Vos’ first Speaker was my carrier — I could recognize the resonance of a fake before my second upgrade.”

Without taking his optics or his hand off of Sideswipe, Prowl signaled behind his back to Jazz.

“You alright there, Darling?” Jazz said, sauntering over.

“Perfectly fine, Dear,” Prowl answered, a strained grin on his face. “Just catching up with that old fling I told you about.”

Primus, he had practiced this and it still sounded so fake. Terms of endearment really weren’t Prowl’s thing. After Sideswipe, they always sounded so manipulative to him.

But it worked. Sideswipe went rigid.

Prowl knew how much this would hurt Sideswipe, dig right into the spark of his insecurities, which is why it was part of the protocol to distract him.

“You two —” Sideswipe looked between Jazz and Prowl. “You’re —”

His hands clenched into fists.

And that’s what Prowl wanted. Jealousy. Sideswipe was too hard to predict, but jealousy — jealousy was predictable.

Sideswipe’s fist relaxed and he touched the side of Prowl’s face, his thumb ghosting gently over the brand his brother had carved. “You’re healthy and happy. That’s good.”

Prowl’s spark sank. This wasn’t the jealous rage he’d predicted.

Sideswipe was forcing a grin on his face, dropping his hand and, stepping back as Jazz arrived at Prowl’s side. There was no protocol to call Jazz off. This was not how Sideswipe was supposed to react — where was the possession? The all-consuming obsession? He wasn’t supposed to accept Prowl’s choice — there was no protocol for —

“Good for you,” Sideswipe said, quietly. “Happy and healthy. You got a frame redesign, and your career has really taken off. You’re making the best of it, huh? Just moving on after what? A single vorn? I really wish I could do that.”

Prowl went to reach for him, but Jazz’s arm looped around Prowl’s waist, and Sideswipe took another step back.

“I’m not… really doing so great — all things considered — if you ever thought to ask,” Sideswipe said. “Was looking forward to spending time with you, but, it’s fine.” He took another step back, the light in his optics wavering in the tears he’d never been allowed to shed. “Sunny said this would happen. We’re always too much. Too intense. We scare everyone away. I feel too much in the wrong way, and I need to learn to turn it off and do my duty killing Quints to keep you all safe, like him.”

A sharp pain stabbed from within Prowl’s spark. That was the last thing Prowl wanted for him. Either of them.

“That’s not… Sideswipe — it’s not —” It was the worst time for his neural net to skip over on itself, and mess up his language files.

“I just, have to go back with Praxus’ Speaker, and she’ll calm down,” Sideswipe said, staring at Prowl as if he was the last taste of freedom outside his cage he’d ever have. “It’ll be fine.”

His fans blasted on high. Static crackled in the air.

“He’s still alive. I sat next to him on the transport. Praxus sheltered him, making his last wishes clear, so Sunny will mentor him,” Sideswipe continued, his optics flaring white as his hands began to shake. “And I’ll be allowed out Cybertron-side again. And I’ll — well I guess I can’t visit you in Praxus, or anywhere now. I’ll just… kick some sand around or something — go to the glass beach for the hundred-thousandth time, and never get to lay somewhere I can see the stars with you warm against my side. It’ll be fine. Sunny will be fine. And everything will be fine. Cybertron will be fine. She’ll calm down, and stop ripping through the mountains to get to Praxus. And the Quintessons will stop getting through.”

His expression became blank, his next words a frightening monotone.

“I just have to bring her Bluestreak.”

The controls to the hanger’s weapons system were ripped out of Prowl’s control at the same time Sideswipe’s optics tightened in a ring, igniting in wild hues of orange and red. Jazz pulled the gauntlet out of his subspace at the same time Prowl commed everyone to take cover, and shouted at Jazz to wait —

It was too late, Sideswipe started shooting with the hanger’s turrets at the same time Jazz shot him with the Polarity Gauntlet. Sideswipe went flying back through his own wild spray of gun-fire, his hole ridden frame — magnetized to the wall.

His helm dipped, optics dark, his chin resting on his chest, as Prowl calculated an approach vector through the defense system’s path, shooting out the turrets and shouting at everyone to stand down.

A spark-beat later Sideswipe’s optics re-ignited, flaring straight to red, the air around him warping as he lifted his head and glared at Jazz through the shadowed-line beneath his helm.

“Sideswipe, stop!” Prowl shouted as he flipped, twisted, and ducked through the spray of bullets, feeling the heat of a laser pass narrowly beneath his doorwings. “It was me, I ordered that. Not him.”

An ominous humming filled the air, and a sphere of distortion laced in crackling static blasted outward. Sideswipe dropped from the wall at the same time the polarity of the gauntlet reversed — sending Jazz and everyone around him upward as a solid mass colliding with the ceiling. A towering column of debris from a recycle bin followed.

The air near Sideswipe shimmered, and Sideswipe didn’t even look to the side as he ripped the Immobilizer from Mirage’s invisible hands, flipping it around and shooting him with the blue, pulsating beam. In a single fluid step forward, Sideswipe repositioned the Immobilizer as a javelin, and launched the relic into the ceiling — embedding it in the gap between Jazz’s legs, a micron shy of his pelvis guard.

It was so much to process at once: the trajectories of the hanger bay’s turrets, accounting for potential casualties crawling for cover. The way Bluestreak had been separated from Hound, Sideswipe keeping him pinned in the centre of the hanger bay.

Prowl was almost to him.

“Prowl,” Jazz’s strained voice crackled in the comms, signal disrupted beneath the pile of others he was magnetized with. “Way to undersell the threat assessment of your slaver-stalker ex we need to keep Bluestreak safe from.”

“I warned you about the tornados, and you thought I was joking!” Smokescreen shouted, risking a peek out over the crate he was using for cover.

Prowl’s spark sank, weighted with daggers that pierced straight through as the weapons systems fell silent. Through the curling smoke drifting over the scorched, hole-ridden floor, Sideswipe was staring at Prowl. Healed, but not whole. His turquoise optics simmering with hurt, caught between the invisible bars of his fate, as Prowl ripped through the wound in Sideswipe that never healed.

“You told them I was a slaver?” Sideswipe’s impeccable tone, and control of his pitch, cracked.

And Prowl knew it would hurt Sideswipe — taint his entire legendary sacrifice — which is why he’d done it.

He’d told himself it was strategic, but he hadn’t prepared himself for how much the hurt in Sideswipe’s voice would cut into him, especially as Sideswipe looked at Bluestreak.

“Is that what our creation thinks of me?” He took a step toward Bluestreak. “Is that what he told you?”

Alone in the centre of the hanger, surrounded by bullet holes that had only ever come close enough to keep him within a circle, isolated from the carefully crafted network Prowl had built to protect him, Bluestreak shook his head.

“I don’t know what everyone’s on about,” Bluestreak said, glancing at Hound, betrayed. “Prowl told me you were an unaligned mech he’d met in the Manganese Mountains during his first command, and that you and your brother were a big influence on making him the commander he was today —”

“I never lied to Bluestreak about you,” Prowl said, moving to stand between Bluestreak and Sideswipe. “I’d never do that.”

“But you’ll lie to everyone else, after everything I’ve sacrificed for —”

“You intentionally left me sparked,” Prowl roared, all his emotions he suppressed over the long decades exploding out at once as he stormed toward Sideswipe. “You created another mythic hero to throw into your grand sacrifice, when I was right there willing to step up. And you left, without a single glance back, or an ounce of support or consideration about my predictions and ambitions, laughing and joking about it to your psychotic brother — who tried to kill me and Bluestreak, because of you, twice! I’ve been terrified he’s going to hunt him down and kill him as a parasitic systems corruption.”

Sideswipe frowned. “Sunny’s not psychotic.”

“That’s all you heard?” Prowl asked, getting up in Sideswipe’s face. “Sideswipe, Praxus is destroyed, and you still don’t think you’ve done anything wrong?”

“I gave you exactly what Praxus needed to be protected and side-step the threat of Starscream,” Sideswipe said, gesturing at Bluestreak. “I’m not the one who dropped him like a hot rivet, and made him learn to reverb destructive feedback when he’s scared.”

“He was a terrified youngling, who’d just seen the only creator he’d ever known get slaughtered in front of him,” Prowl defended. “He doesn’t even know what he did, no thanks to you.”

“When was I supposed to come?” Sideswipe asked. “I promised to do Sunny’s chores and I told you, I don’t get time off. And did you forget my city’s holding back an entire planet swallowing rift ripped in the universe over the Rust Sea? How did you think Cybertron got off the Quintesson homeworld? Honestly, Prowl, we had already survived the hard part: raising him and dragging him through the Gardens for Praxus to call was supposed to be the easy part.”

“What part of raising a sparkling is easy?” Prowl asked.

“Who doesn’t know how to raise a sparkling?” Sideswipe asked back, genuinely baffled.

“Me!” Prowl said. “I was forged. Not sparked. Forged. Everyone in this room, except Bluestreak, Hound, you — and I think Mirage — were forged. Creating life spark-to-spark is barely done anymore.”

Sideswipe blinked, stunned as he processed Prowl’s words, then crossed his arms and cocked his hips to the side. “I feel like that’s a discussion we probably should have had about how cultural norms have drifted, instead of me railing you on your desk for the tenth time.”

“You think?” Prowl snapped, shoving Sideswipe by his broad, infuriatingly attractive, chest. “And it was fourteen, I railed you ten times on the desk — but no, you were too busy being mysterious to give me answers that were actually useful.”

“Bluestreak was supposed to be a surprise, who doesn’t love surprises?” Sideswipe tossed up his arms, turning and walking away a few steps before coming back, poking Prowl on his bumper. “And you loved mysterious.” He blew a harsh gust of air from his vents as he crossed his arms again and scowled. “It’s exhausting living up to your expectations, you know that?”

“I’m exhausting?” Prowl asked, gesturing at himself in disbelief. “I’m the exhausting one? I studied your language —”

“Which you butchered —”

“Your twin tried to kill me —”

“Doesn’t make you special. He tries to kill me all the time —”

“I understand his impulse!”

“See?” Sideswipe said, gesturing between them. “We’re connecting. Understanding each other and what went wrong.” A hesitant, vulnerable expression formed on his face. “Do you still…” he winced, bracing as he glanced up at Jazz still magnetized in the pile of other mechs. “Even… despite your better judgement?”

“You are the most infuriating mech I’ve ever met!” Prowl said, rubbing at the base of his chevron. “No one gets under my plating like you.”

“But…” Sideswipe hesitated. Blinked. “Do you mean under your plating in a sexy, seductive way?”

“I didn’t —”

“But now you’re thinking about it.” A hint of an encouraged grin was forming on Sideswipe’s face. “And you miss it.”

“You are the worst!” Prowl crossed his arms under his bumper then turned away, hiding how his face was heating.

But that just announced it to everyone gawking from behind their cover throughout the entire hanger bay.

“I would not be opposed,” Prowl said, quieter, slowly glancing at Sideswipe over his shoulder. “If our schedules align, and the war permits, to sit under the night sky with you and have you tell me what the star pattern in the cave mural your brother made means.” He turned back toward Sideswipe. “I have never been able to align it with our constellations, even accounting for stellar drift, and that has been irritating me as an underlying calculation running through my neural net for nearly a century now.”

“Star pattern on the mural?” Sideswipe asked, optics going distant — for fucksake he was asking Sunstreaker, outsourcing his memory and this moment to his twin. “Oh, that’s —”

Prowl placed a finger on Sideswipe’s lips, shutting him up.

“Save a little mystery until our date.”

“You gonna bring those boring old cuffs, tie me to a chair again, and finish what you started a vorn ago, Commander?” Sideswipe asked, nipping at Prowl’s fingertip.

“GROSS!”

Prowl’s doorwings shot up, his joints locking as he realized Bluestreak had snuck closer in his unnerving way, to listen to what they were saying.

Sideswipe kept his optics on Prowl, still grinning, unashamed, as he reach out and grabbed Bluestreak from the top of his helm, turning him around. “That’s what you get for snooping.”

Bluestreak was so shocked it actually worked for a second and he turned, but then he was ricocheting right back.

“You were fighting about me a second ago!” Bluestreak said, knocking Sideswipe’s hand from his head. “What don’t I know that I did? What does Praxus have to do with it — Are you really from a city in the Rust Sea? Prowl used to tell me myths about —”

As Bluestreak burst with questions Prowl did not want to answer, Sideswipe took Prowl’s hand in his, and brought his knuckles to his lips, giving it a kiss.

“Go pack your things, Bluestreak,” Sideswipe said. “I’ll answer all your questions later. Your creators need to be gross first to make up for lost time.”

“Why am I packing my things?” Bluestreak asked, his doorwings cycling in building anxiety. “Prowl?”

At the same time, Prowl pulled back his hand from Sideswipe. “No.”

A groan left Sideswipe and he stared up at the ceiling as if asking Stormsinger for a rift to open him up, and swallow him whole.

“Prowl,” he ran his hand down his face. “I have to take Bluestreak with me. He’s been called, and he’s the only one —”

“Bluestreak is fine as he is,” Prowl insisted. “He is an accomplished sniper in his own right, one of the best we have — a path he pursued on his own.” He stepped between Sideswipe and Bluestreak again, crossing his arms beneath his bumper. “I agree he needs to learn control, but Sunstreaker can come here to —”

“Would you let me finish?” Sideswipe moved to push past him, and Prowl continued blocking his way. “Stormsinger is on a rampage — she is out for blood — trying to get to Praxus’ corpse. Sunny and I can barely keep her from both ripping the planet in half to get to him, and keep the Quintessons out at the same time — let alone get her to calm down long enough to listen to the message Praxus left her when he called.”

“What message?” Prowl had poured over every inch of Praxus. There was no message. Just destruction. Senseless destruction.

A second later, Bluestreak lost all luster.

“Corpse?” His vocalizer cracked on the word.

Prowl whipped toward him, fuel pump racing. “It’s nothing. I’ll explain it later. Not here. In private.”

“You — you said corpse.” Bluestreak stared at Sideswipe. “Why… why would you call it that?” His optics darted between them, then he sought out Hound, who shrugged his one shoulder. “What corpse? What is everyone on about? Was it because Sideswipe was just dead against the wall a few minutes ago? And why does Praxus have a… corpse…”

It started with a high-pitched ringing that made everyone in the hanger flinch.

“Bluestreak,” Prowl said, wincing through his own systems shuddering from the reverb. “You need to calm down and regulate your vents.”

No one else but Sideswipe could hear the piercing noise setting Prowl’s neural net on fire. But everyone in the room could feel a sudden unease within their spark chambers.

“He do this often?” Sideswipe asked, as Bluestreak’s doorwings stopped cycling and locked.

Prowl reached for Bluestreak to anchor him, but the Last Survivor of Praxus was past processing his surroundings already. His vents seized, his armor plates splitting along the seams as energy discharged in uncontrolled bursts that send Prowl back stumbling.

Sideswipe caught him, a steadying hand on Prowl’s elbow, sending a counter-frequency to dampen the feedback in Prowl’s head. The frequency changed, mutated in reaction to Sideswipe’s, and Prowl’s vision split in flashes of light as Sideswipe cursed, locking in on Bluestreak like he was a threat that needed to be put down —

“Don’t hurt him,” Prowl said, clutching Sideswipe’s arm as he rose to standing.

“If he wakes Iaconus, without a Speaker of his calling,” Sideswipe snapped, “You are going to have bigger problems — he’ll crush half the population before he even stands —”

A pulse burst out of Bluestreak as his optics compressed to a halo of red. A low, rolling wave that reverberated in concentric circles through the metal beneath them. Lights flickered, and every sound in the room warped under the sudden increased pressurization of the air.

Something popped in Prowl’s helm, flaring in a scorching heat down his spine and through his doorwings. Bluestreak gripped the sides of his helm, his feedback screaming through the overhead speakers.

“Stop! Just stop it —” His voice was strangled static. “Stop hurting him — you’re ripping him apart — this isn’t it. This isn’t — it hurts. It hurts too much —”

Bluestreak convulsed, blue light arching between his seams as Prowl felt his optic flare red. Prowl’s vision cracked — fractured into infinite spiraling shards of possible futures — flashing by so fast it felt as if all of him were left behind, except the puddle of purge.

A shadow crossed the blinding light. Prowl struggled to focus on the blurry form he swore was Sideswipe.

“You’ve got a nasty recoil in you, boy.” Sideswipe’s voice rumbled in a deep bass, distorted.

“I am not your boy,” Bluestreak snapped, blasting Sideswipe back.

Sideswipe twisted mid-air. Landing in a crouch. His optics red beneath his helm as he grinned, impressed. A vibration ripped through the ground and Bluestreak was pulled toward Sideswipe as if he held the Polarity Gauntlet.

The sound ripping through Prowl’s helm cut off, and he held his left optic as he stumbled to standing. His limbs moving on a delay as if dragging them through sand.

“Let go of me! Don’t touch me!” Bluestreak struggled against Sideswipe’s iron grip, hands pinned behind his back, his electromagnetic pulses lashing out wild around him. “Just because you ignited me does not make you my creator!”

“So feisty,” Sideswipe snapped his teeth by Bluestreak’s audial, his fangs flashing as he invaded Bluestreak’s personal space. A low, warning bass note rumbled out of him. “Your resonance has quite the vicious bite.”

As Sideswipe peered over Bluestreak’s shoulder, locked in on Prowl, a shadow fell over Sideswipe’s face. His optics were flared through their full spectrum of colours, his voice fractured into harmonics — two voices — not three — as one.

“He gets that from me.”

Prowl froze as if his pedes were suddenly magnetized to the ground. “Sunstreaker.”

“Prowl.” Sideswipe’s helm inclined a fraction, and Prowl’s name had never sounded so flat in Sideswipe’s vocalizer.

“You’re speaking out of your brother like a Titan.”

That did not bode well for how far Sunstreaker was drifting beyond himself.

“I don’t trust him around you unchaperoned,” Sunstreaker said, flicking the back of Bluestreak’s helm in a dull thunk. “Look what happened last time.”

The flick hit like a tuning fork wrapped in crackling static — Bluestreak’s optics snapped back to his turquoise blue with only a hint of a rim of rust. He rubbed at the back of his helm.

“Ow.” He twisted in Sideswipe’s grip, incredulous. “That hurt. Did you really just flick —”

Sunstreaker grabbed Bluestreak by his helm’s crest and forced his head back.

“Well, he’s not hideous — which he definitely didn’t get from you,” He traced beneath Bluestreak’s optic as if examining the quality of his new medium; when Bluestreak flinched, Sunstreaker only tightened his grip. “Makes teaching easier if I can actually stand to look at him.”

Prowl’s doorwings flared. “Don’t you dare carve into his face —”

“With what?” Sunstreaker shoved Bluestreak forward, letting go of him as he raised Sideswipe’s hands. “These blunt things? Sides always complains he can never pick things up right when I sharpen his fingertips —” Then Sunstreaker crossed his arms and dropped to a mutter. “He just doesn’t want to be even mildly inconvenienced for the sake of a symbolic aesthetic.”

The glare he aimed at Prowl was scathing, as if his own muttering had been an intrusion into his privacy.

Bluestreak just stood there, like he had suddenly lost all his survival instincts, still rubbing at the back of his helm, his expression sour.

Hound, bless him, was motioning at Bluestreak to come over to him.

“What do you want?” Prowl asked, because Sunstreaker didn’t just stick around talking out of his brother, using him like a Titan, for nothing.

“To stop having to mop up after Praxus’ messy choices for one,” Sunstreaker said, briefly shifting his focus from Prowl’s right optic to his left. He reached out, grabbing Bluestreak from taking more than a step toward Hound, and hauled him back by his collar-faring. “That includes you, Sparkbite.”

A spiral of light tore open behind Sunstreaker. Before Prowl could get his sluggish limbs to move, Sunstreaker hurled Bluestreak into it.

“No!” Prowl shouted, the word splintering. His spark surged into his throat as he lunged —

Sunstreaker’s kick sent him skidding back across the floor. At the same time, Bluestreak’s grappling hook shot out, catching the beam overhead. He jerked to a halt, half in the portal.

Without even glancing away from Prowl, Sunstreaker’s Void Blade snapped out of his wrist, slicing through the cable.

Prowl watched, scrambling through permutations in slow-motion as Bluestreak fell into the spiraling portal. His optics flared, confused and terrified, as he sank into the hole cutting through dimensions, until only his arm was still reaching —

Hound slid in, caught his wrist —

Then the sound that came out of Bluestreak didn’t belong in Prowl’s careful web of predictions. A howling scream of pure agony.

The portal sealed, cutting the tortured sound in half.

Hound crumpled to his knees. His remaining arm hung limp, the other still a sparking stump. His stare vacant — Bluestreak’s severed, bloody hand still holding his — locked up in shock.

Prowl couldn’t cycle his vents.

“Sunstreaker!” Prowl roared, his voice crackling in rage, recalibrating his systems. “What did you?”

He surged forward, fury pouring from his every, overheated seam.

“You cannot just —” he clawed at Sideswipe’s chest as if he could dive into his spark and fall into their city. “Bluestreak is not ready — he doesn’t even know — bring him back and let me explain. With Sideswipe here, not you!”

In the face of Prowl’s pleading, rationalizing rage, Sunstreaker regarded him as a god looking at an insect. Through Sideswipe’s face, the apathy was unbearable. Sunstreaker seemed only vaguely annoyed Prowl was touching him. Putting more scrapes on Sideswipe’s finish that he’d only have to sand and polish out. Bored. As if he hadn’t just closed the portal to cut off Bluestreak’s hand, while wearing his creator’s face and frame. How long would it take for Bluestreak to understand Sideswipe wasn’t the one who’d done it, if Prowl wasn’t there to explain?

When Prowl did not stop trying to negotiate with him, Sunstreaker had had enough. A strong wind built, pushing Prowl back a step.

“Bluestreak will never learn control if you try to soften the tragic nature of his calling,” Sunstreaker said, unconcerned as Prowl glared through the mech he loved at him. “The melody underlying the universe is neither cruel, or caring. It is apathetic to our existence. It is not in a Titan’s nature to care.”

He shifted his flat, multi-hued gaze from Prowl’s blue optic to his red.

“Praxus is a Titan that, despite his nature, chose to care,” Sunstreaker said. “And he cared too much. He was tormented by all the pathways not taken. All the dead he could never save. The sacrifices in the probabilities for the hard choices. He could not accept their fates.”

Sunstreaker leaned closer.

“Sound familiar?” He asked. “Or do you need me to peel open the waveforms of your spark again, and hold them to your lips for you to recognize the taste?”

“Choice is not an infection, Sunstreaker,” Prowl said, fists clenched, knuckles creaking. “Bring Bluestreak back here, let me and Sideswipe talk to him, and let him choose! It costs you nothing.”

“It costs me everything!” Sunstreaker growled, a staccato to his words. “And now, it cost you everything. I walked the remains of Praxus’ Crystal Garden. I found the message Praxus left for Stormsinger.”

“There was no message!” Prowl said, wishing strangling Sunstreaker while he was wearing Sideswipe like a casual new alt mode would actually throttle him. “It was an accident.”

“Nothing with Praxus is an accident,” Sunstreaker said, as he began to circle Prowl in a slow orbit. “In Praxus’ final moments, he triggered a shield made out of Stormsinger’s own crystal carapace armor, signaling for her aid. Praxus protected his Speaker within Stormsinger’s shield, while destroying himself.”

“Bluestreak destroyed Praxus,” Prowl said, the words hissing low in the narrow space between them. “He remembers it — it was impeding his function so much, I had to have it suppressed —”

“Oh, it was Praxus,” Sunstreaker said, his scorn so foreign on Sideswipe’s face — falling so callously from his lips. “It’s always Praxus. He didn’t like that Stormsinger wouldn’t answer his call if he didn’t call ‘properly,’ so he just used Bluestreak as his inexperienced hand to do it. It was that very inexperience — that spark wrenching tone of innocence beneath the sound of his destruction — that made his final design resonate, and once Bluestreak helps get Stormsinger calm enough to listen to it — she’s going to be so impressed with the tragedy in the melody, and fall madly in love with him all over again.”

“Why would he —” Energon rushed from Prowl’s face. His frame going cold.

Bluestreak hadn’t — but in the same way, he had — except as an instrument. Tuned in such a way to make even Stormsinger’s apathy crack.

It wouldn’t make Bluestreak learning he’d been used to do it any easier for him to hear. To process. That the Titans saw this as an act of love on a cosmic timeline.

“Because the universe is apathetic,” Sunstreaker said, not knowing the connections Prowl had made on his own. “And Praxus cared too much, are you not listening? Are you blind? Can you not see the artistry in his final brush stroke? The spark-stabbing moment of crescendo. The fury. The betrayal. The sacrifice. The beauty of the symmetry of his design. In leaving only a Speaker for a dead city in his remains — while Stormsinger was willing to stand by as the paradise he created and she sacrifices for you all descends into mass slaughters and war — Praxus has called forth the only voice he thinks Cybertron needs to hear: a Speaker for the Dead.”

“Artistry?” Prowl snarled, becoming more incensed with every moment of tragic romantic poetry Sunstreaker inhaled like Praxus’ destruction and Bluestreak being used as an instrument of it — was life. “Artistry!”

“Bluestreak killed Praxus? All of it?” A quiet, haunted whisper came from the floor nearby.

Prowl’s spark lodged in his throat as Sunstreaker zeroed in on Hound, still kneeling where he’d collapsed. Still holding Bluestreak’s severed hand.

“Who the frag are you?” Sunstreaker tilted his head to the side as if listening to Sideswipe within him, then sighed, another portal flared in the same place as the last. “Alright fine, you too ‘Kaon,’ get in.” Sunstreaker placed a hand on Prowl’s chest. “Not you.”

Hound hesitated for only a second to tighten his grip on Bluestreak’s hand — not looking back to Prowl for permission as he launched in a giant leap through the portal.

It closed, and a hint of a grin lifted the corner of Sideswipe’s face in Sunstreaker’s expression.

“It’s always funny when they think they have to jump in it like a puddle,” he said, then realized he was trying to share a joke with Prowl while still touching him, and the expression instantly wiped off his face.

He jerked his casual touch from Prowl’s chest like Prowl was coated in a rust infection, and he reached for a polishing cloth to wipe it — then cursed, digging around in Sideswipe’s subspace.

Under his vents, Sunstreaker muttered. “You never leave anything where I —”

His head snapped up, polishing cloth forgotten. Shouts followed shortly by a crash and Sunstreaker narrowed his optics to the pile Jazz was groaning in, or more accurately, the Polarity Gauntlet, and the Immobilizer.

“While you were spending your time gathering relics,” Sunstreaker said curiously, raising a hand — the Immobilizer flew into his grasp. “Did you happen to find the forge Solus Prime stole from me?” He set the blunt end of the Immobilizer on the ground and raised his other hand above it, using it as a measuring stick. “Giant hammer, about this big, gold and silver — lent to me to hold in trust. It would make Bluestreak’s path easier if you found it before Helex’s next Speaker’s rise.”

Baffled at the abrupt change in topic, and because Sunstreaker said it would help Bluestreak, Prowl could only think to ask: “How did it get stolen?”

Sunstreaker shoved the Immobilizer into Prowl’s hands, exasperation blazing through Sideswipe’s features.

“Sideswipe,” Prowl said, his fingers flexing around the Immobilizer as he answered his own question, because of course that would be what had happened.

“Sideswipe,” Sunstreaker echoed his brother’s name like a curse that had worn out all meaning.

The hanger bay shuddered with a sudden bang — as if the universe itself flinched at the echo, recognizing the common underlying refrain of Sunstreaker cursing Sideswipe’s name within its melody — and flinching away from it.

Then came the light, a searing, silver-white, followed by the shriek of metal as an immense sword carved through the reinforced hanger doors like aluminum foil. Three slashes. The cybersteel buckled forward, crashing to the floor in a riot of sparks.

Through the smoke and molten edges, a silhouette emerged, and in stepped Optimus Prime — the Autobots’ moral compass. Shining, chivalrous, and indomitable. The kind of mech gravity shifted to make room for in the universe. His armor and massive sword gleamed beneath the landing bay’s flood lights. Blast mask sealed across his mouth, his optics narrowed in their direction — an avenging hero of legend they scored stories and songs about in the stars, ones that never stopped falling from the populous’ lips.

Sunstreaker growled in disgust.

“You gave the Star Saber to a Prime?” Sunstreaker tossed up his arms. “Ugh, this is why I never go out.”

A portal flared beneath Sunstreaker, and in a flash of blinding light, he was gone.

Sideswipe dragged back into their city with him.

And Prowl was left as the target of Optimus Prime’s confused silence — left to draw the connecting lines no one else would, trying to chart a story through a shifting sea of probabilities already moving beyond his reach — a narrative.

A myth.

That would explain everything.