Chapter Text
The first time they switched, it only happened for a minute. Whatever magic in the universe that created the soulmate connection was benevolent enough to wait until the younger of any pair turned six before a first switch could occur. Just old enough to be able to speak and communicate with the world around them, but young enough to establish a fast bond. Of course, the first few swaps were always quick. Just enough to let you know your other half was out there and alive without adding unnecessary mental strain from such a new experience.
Marinette had only turned six just that morning when she came to in a boy's body, standing in a bathroom and looking down at a woman slumped in the bathtub, needle sticking out of her arm. She couldn't process what she was seeing, not really. Only doctors and nurses used needles, and they never left them in, so why did this lady have one? Did the nurse forget it there and she was too afraid to take it out herself? That's okay, Marinette was brave. She'd take it out for her.
Leaning over to grab the end of it, she blacked out only to awaken sitting up in her bed. Blinking back the confusion, she ran downstairs to tell her parents what she experienced, leaving out the woman with the needle. Her mama and papa needn't worry. She's sure the lady would be just fine once whoever that boy she woke up as took it out.
…
It took three years for a swap to last more than a few minutes for her. Her parents assured her that this was normal and the switches with her soulmate would get longer once they were both a little older, usually around ten. This time, it lasted over an hour. She was only nine and quite proud to be considered strong enough to hold a connection earlier than average.
Only, she woke up in an abandoned building.
This couldn't be right, he was in a home last time and that was only a few months ago. Maybe her soulmate just got lost and decided to take shelter for a while? The gnawing hunger said otherwise. Lifting her shirt, she could see the outline of her ribs and began to understand. This wasn't a mistake. He must've been starving for quite a while to be so thin. That much, she realized on her own. The pain of hunger struck up again and she felt tears well up in her eyes, not only for the tightness in her stomach, but for the misery of her poor soulmate.
When the pull to switch started to tug at her mind, she resisted, hoping the boy would go and eat with her family. It was almost dinner time and he deserved a real meal, even if it wouldn't transfer with him when he reentered his body. She prayed with all her might that at least this would offer him some small comfort. Surely he felt the tug too and knew she was holding back for him.
Marinette wished she could leave some sort of note, but upon scavenging the backpack she finally noticed beside her, she found it filled with only necessities. She couldn't fault him for that.
His survival was more important.
Her strength wilting, she knew she'd let go soon, her last thought a hope that he enjoyed his time as her.
Coming back to her own body, she carefully hid any reaction and resolved not to tell her parents, not wanting them to know the horrible truth. For what could they do? They didn't know the boy's name, where he lived, or even how to find him. And if the sounds and words she had heard in the last few switches were anything to go off of, he wouldn't speak French either.
Based on her parents' behavior, they hadn't noticed. Perhaps they just thought she was feeling a little down and didn't want to talk. That was fine by her.
…
When she turned 12, something changed. Marinette had grown accustomed to waking in random places hungry, sore, and cold. Over time, the hunger was less, so surely he found some reliable source of food even if it wasn't enough to curb the ever present twist in his lower gut. He also seemed stronger over time, little bruises and scars starting to accumulate from what she could only assume were street fights. She considered herself lucky the swap never occurred during one of those.
This however? Was completely different. Enough to give you whiplash.
She found herself in a soft bed with plush blankets and down pillows, the room surrounding equally as lavish. For a moment she wondered if perhaps they had a third soulmate who was much younger than them, but looking down at herself, the frame and scars and structure were all the same.
Not sure how to behave in this new environment, she simply sat there, unmoving, until a nagging in the back of her mind told her to check the drawer of the side table next to her.
Reaching in, she found a crisp, folded up piece of paper with her name scrawled across the top.
A note from her soulmate. Opening it up, she thanked everything she had that she realized he probably spoke english three years ago and began studying it extensively. Reading his letter was slow going and took multiple tries, but she eventually figured out the jist of it even if she was clearly missing some of the more obscure words and proper conjugations.
He was thirteen and had been taken in by a man of wealth, Bruce Wayne. This was home now. She would wake up and not be homeless now. He was sorry. Something about her deserving better. His name was Jason. He was very sorry. A man named Alfred was a good person and trustworthy. She would like him. He hoped she liked him.
The letter, as convoluted and confusing as it was at times, broke her heart.
Shuffling through the drawer, she pulled out a notebook and opened it to a random page and grabbed a pen. She was embarrassed to say that her note was probably more confusing with its broken english, but there was no way he learned French while living on the streets, so she did her best to let him know that he shouldn't apologize. He had no control over his situation and that she hoped he found some reprieve in his time in her body. That she cared and was so very happy for him to have found a home. That it was wonderful to know he would sleep in such comfort with a full stomach and a warm blanket and people who cared for him keeping him safe. That he deserved to be happy and thrive without the fear of where he would sleep that night, when his next meal would be. That she was happy to be his soulmate, no matter what.
…
After that, they switched more sporadically. She learned that muscle memory was an amazing thing. Nothing quite like coming to while sparing with a full grown man. And not realizing that it was a spar and not some man trying to actually take down her soulmate.
The next time they switched, she found a note with profuse apologies and a brief explanation as to what was happening. That was how she began her training with him. She asked her Maman about getting into martial arts so she could keep up with him and continue his training if he got stuck in her body for more than a few hours.
Obviously her parents knew she had a soulmate and presumably his new parental figures knew he did too, but they made sure none of them could ever tell when a switch occurred. Letters were made detailing their usual reactions and attitudes and way of doing things. Letters were burnt to never be seen by another's eyes. Instinct is what helped them the most to hide their secrets. While Marinette had always been a generally open and honest kid, this was between the two of them and no one else needed to know their business. Especially with his new role as a vigilante in training.
…
When she turned thirteen, that training took a new meaning for them both. He had been Robin for half a year at this point, with only minimal switches during actual patrols, when she received Tikki.
Directly after defeating Stonehenge, she wrote out a long winded letter in near perfect english- written grammar rules would forever confuse her- to him despite his immense progress with French and placed it in a secure lock box they used in her home for communicating and instructed Tikki that upon sensing their switch, as the magic being assured she could, to stay hidden until he finished reading it in its entirety.
Of course things don't work out that simply and they switch in the middle of an akuma attack.
Looking back on the footage, muscle memory once again saved their lives, but she still feels horribly about how he got tossed into it. Tikki assures her that he was okay and read her note and wasn't angry with her. That she had been forced into this position in both their lives now, yes, but not at her.
She could only count her blessings that they both already had a background in fighting at this point. If her mentor took note of her easy transition into superheroism, it was easily chalked up to her martial arts classes, even if she had only been in them for about a year. If his mentor noticed his increased agility and critical thinking due to his time in her body fighting akumas and using convoluted lucky charms, he likely assumed it was his own guidance finally taking hold.
…
The last time they switched, Marinette was fourteen and in class. It was first thing in the morning, attendance already taken and lessons underway. By all accounts, Jason should have been asleep, what with it being around two a.m. in Gotham. Switching at this time wasn't unheard of though considering their lifestyles, so upon feeling the small tug in her mind that let her know she was about to be somewhere else, Marinette placed her tablet down and leaned back in her seat so he wouldn't accidently draw attention by tossing the tablet or falling back upon waking as her. Then she waited.
The first thing her disoriented mind picked up was the feeling of a metal bar launching into her stomach which… admittedly wasn't an entirely new feeling, though it usually occurred in her own body and not through his.
Okay, so a fight, she could handle this.
Her arms wouldn't move though.
They were strapped down, as were her legs and the metal was pulling itself away from her. So she wasn't launched into a steel bar or batted across the city. This was purposeful, she thought as the bar slammed into her stomach once more, erupting in pain without the protection of a magical suit. Despite the fear now coursing through her, she opened her eyes.
Or rather, attempted to.
One was swollen shut and as she became more aware, she could feel broken ribs, a broken leg and arm, the pulsing of half her face. As her one good eye opened, the room spun, but she could see a man in a swirl of purple and green standing over her body. Her soulmate's body. As soon as the world stopped, she came to focus just in time to see a crowbar swing down into her throat, cracking the windpipe. As she struggled for breath, the tugging came to the back of her mind once more, the strain on his body too much to hold her mind in place.
She pushed it back, focusing more on forcing him back into her mind than breathing at this point, ignoring the blows raining down on her.
She was numb by now anyways.
She could feel Jason trying to claw his way back, pushing against her will to switch back, but at this point, this body wasn't strong enough to allow a switch. She was stuck in him and he in her.
Good. Jason had been through enough. She could endure this for him.
Distantly, she noticed the beating had stopped. Hopefully that meant Batman was here now and would take her away from this place. To a hospital or even to their personal surgeon, whatever their name was, she could never remember. It'd be over soon and she could rest through the pain until Jason's body was healed. Then they could switch back. When the pain was but a distant memory.
Smiling to herself at the thought, she managed a tiny smile, not hearing the explosions in the background until the flames were upon her.
And then she was gone.