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Chapter Text

Keith could seriously slaughter the humans holding him prisoner...

Keith's a (half) mer stuck in this stupid tank. These humans apparently think he's incapable of taking care of himself, especially out in the ocean. Which was understandable at first. The attack on him before the humans rescued him was brutal. He barely made it out alive. But he's fine now, even with the scars and stuff.

WHY WON'T THEY LET HIM GO!?!!!

He's got his own tank at the end of the aquarium. It's actually really a petting zoo for mers though. He's not stupid. Him and the others are entertainment for the stupid humans fascinated by their species. He sees the people gawking at them. He hates the stares and the points and the people who rap on the glass ridiculously. But more than that, Keith hates the other mers. They're stupid enough to not mind the tanks, or worse, love the attention. He can't get along with any of them, as they quickly found out. He might be fairly small, but he's tough.

That's why he has his own tank. There's plenty of room and food. He argumentively could live here just fine all his life. But he doesn't want to. He wants to soar through the water, chase his prey with a challenge, explore the deep depths for abandoned ships and worlds...go back home to his clan...

They've got to be missing him. Frantic. His father would be worried. It's been a bit since he visited his dad. Hopefully his mom keeps him updated...

A slap on the glass pulls him out of his head as he swims around, eyeing where it came from. He huffs as a woman stands there, ogling him like some type of mystical creature...granted, he kind of is. But he doesn't like it. He's one of the most popular mers there for some reason. Everyone takes an interest in him. Maybe it's the scars decorating his cheek, shoulder, fins, tail...maybe it's his colorful shifting black/red/purple scales...maybe it's something else...all he knows is his tank is popular and he hates it.

He's never been a people person.

The woman does something ridiculous which drives on his nerves. How would she feel if their situations were switched and he was knocking obsessively on her door? He snarls before swimming up and over the tunnel to the other side. Unfortunately, he has no shelter from the onlookers. The tanks are designed to be viewable 24/7. He despises that too.

And POSEIDON'S BEARD, WOULD THE BITCH STOP KNOCKING ON HIS FUCKING TERRITORY!!!

He rushes at the glass, snarling and hissing loudly, scaring her as she yelps, tripping onto her ass on the floor. Thank goodness she's not stupid because she quickly fades into the crowd. He glares for a moment before going back to his drifting. There's really nothing else to do.

All these people are driving him crazy. He doesn't feel safe. It's too open. He doesn't have the supplies for a proper nest. It's too open. He's...

Oh fuck...he's going into heat...he's been in heat here before. But that was because he was growing. Now he's definitely hit puberty, so he'll experience his first full-on heat. And he's going to die...not literally but still.

Either these humans didn't know about heats and ruts in the occasional species or they don't care because Keith doesn't have any of the needed resources. He's hungry and feeling very territorial. He doesn't have much to make a nest and nothing to satisfy himself and the humans can watch him be in heat the whole time. Heats are private between mates or family members. Not weird strangers.

He rummages around his messy nest. All mers have resting places. But nests are something else. They're intentional and built for the mating process or platonic help. And his is terrible. How would a mate ever want him with a useless nest like this one! How-

He snaps at someone else, making them jump back. It's a kid. He feels kind of bad. He kind of doesn't mind the little ones. But at this time, he doesn't care. They're in his space. In his turf. He would kill another mer for being in his territory. He has.

He goes back to his nest. His heat is only going to get worse with time. And he doesn't even have anything to fuck with besides his fingers and that weird shaped thing in the middle of the tank that is probably supposed to be a piece of wood? Keith doesn't want to use it. But when he's in heat and half out of his mind, it'll look like a good thing.

He makes a note to toss it into the furthest corner away from him so he's not tempted. He doesn't need an infection because he cut up his pouch and birthing canal.

.....

Keith starts to feel his heat. He starts feeling hot. He's even more territorial. He's slick all the time anymore, pheromones ripe and drifting in his water. He's getting aroused randomly.

There's one human who thrills him though. The man is newer but has been in quite a few times now. His few friends are annoying but Keith's eyes are on him. The man is tall with a strip of silver bangs, mechanical arm, and a gentle look on his face. He never approaches Keith's tank, but he clearly watches him...

Keith swims to the top of his tank. It's sealed tightly, just maybe a foot of air inside. They learned quickly that Keith is unable to use the air in the water. He lacks gills, a sign of his half-mer status. Unfortunately, he hasn't been able to pop the lid off and escape. He's tried multiple times. And it's not like nobody can see him up here. They can. Even now.

He's tired of this! He wants to be free! He wants a nest! He wants to be fucked good and properly within an inch of his life! Was that SO HARD TO FUCKING ASK FOR!?!!!

He slams into the lid. It doesn't give. He doesn't care as he does it again and again. He needs out. He wants out. Now!

He barely notices when his arm starts to bleed. Or when the alarms go off. Or when the sound of people entering the room above him happens. He slams and bites and slaps on the lid over and over.

It pops open suddenly. Keith isn't ready for the lights or sounds or smells or-

He yelps as something wraps around his neck. Quickly adjusting, he sees the horrible rope pole thing they use on the unruly mers. He hates that device. But he hates the smell of strangers in his territory even more.

He hisses loudly before lunging for the pole. He yanks it out of the human's hand before trying to dart back down to the bottom to remove it. The humans have a idea as two more close around his wrists. He struggles and fights. Someone gets a hold of the one around his throat, holding him steady as the other two attach to the tank, unmovable. Keith fights and fights and fights until he can't, letting out a pitiful wail. When he calms, the humans do some stuff. They patch up his arm, take some tests, and inject him with something. He doesn't have to wait long to know it's a sedative as he drifts to sleep...

Chapter Text

Keith wakes at the bottom of his tank. It's a slow process like swimming through thick sludge. He yawns before moving a bit, feeling...weird. Part of it is his heat. But part of it isn't. Maybe from whatever they knocked him out with?

Keith wakes more, grabbing at his neck, hissing aggressively as metal meets his clawed fingers. He feels all around it, noting the circular shape.

A fucking collar...

Keith swims around to wake up more, yet the slight haziness never goes away. He's pretty sure it's not the heat. Although he does still feel like he needs to be fucked out of his mind. That's the heat. But the weird feeling stays. He ignores the food he sees before swimming forward. Blinking, he sees people in his tank area, like normal. A spike of anger and territorial instincts takes over but falls short suddenly as he grows tired again. He drifts around in a small haze, not really even noticing that he is definitely aroused.

Some time later, he wakes more. Blinking, he frowns as his mind comes back to mostly full awareness. He's starting to burn up with the heat. His insides feel like fire, needing something to fill him to the brim. He can smell his scent everywhere and it doesn't smell right. It's soft. Gentle. Keith's scent is never soft or gentle. It's strong. Something is wrong.

He starts for the tank top. He's going to need air at some point. But as he swims closer, he gasps. Something weird happens the last few feet from the tank top. It suddenly feels like he's fighting a strong current. He presses on, inching up and up an-

He quickly sinks with an exhausted whine, landing on top of the tunnel. It takes a moment for him to get his bearings and he feels as his slick and pheromones pool and slide down the glass. He huffs in amusement, knowing they probably won't like that because slick won't naturally dissipate in the water like other substances do. And then it hits him. He's still breathing. How?

The collar?

He should have needed air by now. He doesn't know how long he's been out. And the haze makes time weird. And he gets the feeling he's gone longer than he normally would. Even the humans here would know how long he can stay underwater. So the collar must be...injecting oxygen?

He doesn't care as he curls up on the spot.

It's too open. He's too scared to do anything about his heat. Heats are very private things. He can't just fuck himself in front of random no ones. And yet, a spike of hotness slams into him suddenly. More slick slides out as he wails slightly. Forgetting all about the previous thoughts, he quickly slips a few fingers into his canal, just barely remembering to sheath his claws before thrusting.

It feels so good. Like dousing an overheating body with cool water. He wriggles his hips, moving his fingers around aimlessly, just doing anything to help cool his heat some. Pleasure spikes in his gut, spreading outward to his limbs. He gasps before moaning quietly, going at it harder. He's edging to the first orgasm when everything grows fuzzy. He whines tiredly before sliding into a weird half-asleep state.

When he comes back, he whimpers. He's hot and burning up. He starts pumping back into his body, but it hurts more than it helps. He whines loudly before he notices the people under him watching him. Too many eyes on him. Heats are private. Heats are for mates and family. Heats are painful. Heats are intimate. Heats ar-

He darts for the furthest corner away from the humans. He shuffles everything around, trying to make a nest. He fails spectacularly, wailing a bit before turning his back to the crowd, fingers deep into his hole. It never helps though. He gets close to an orgasm, but it evades him as he ends up mostly half-asleep. Each time it happens, the pain grows. So does his body heat.

He eventually figures out that it's his collar. It's injecting him with some kind of sedative whenever he gets worked up, whether that be in anger or in pleasure or maybe even pain. And it's not allowing him to take care of his heat.

He whines loudly as he fucks himself on his fingers more. He edges closer and closer, pain cooling down to a pleasant warmth. He's so so so close when his world grows hazy again, fingers slowing along with his hips. He snarls and screams as the haze falls over him. It doesn't get far before he kind of drifts off again.

.....

Shiro likes the aquarium now.

His friends convinced him he needs to have an activity outside of work. He's a workaholic. Shiro knows he is. But he likes it that way. Routine helps him stay well. And if that means working for about 12 hours a day, at least 6 days a week, who's to say he can't? But he also knows his friends are right. He doesn't really do much outside of work. The occasional coffee shop. Read a book here and there. All that stuff.

So the aquarium it is. It's Matt's idea really. Shiro isn't all that into the ocean. Or its creatures. He'd rather look at the stars. But he has to admit, the mers are really something else. They're all rescues of one or another. He doesn't know how he feels about the encagement though. He was once a prisoner himself, hence routines. He gets the feeling of being trapped.

But none of the mers seem like they want to be anywhere else. They swim around in groups, playfully nipping and laughing with each other. Some of them clearly loves the spotlight as they stay close to the glass, showing off for the people watching.

Shiro sees all kinds of colors and shapes and past wounds.

But it's the mer in the last tank that draws his attention. The mer is beautiful in a sharp way. He's slim, made for speed and agility. His scales shimmer between ruby, amethyst, and onyx gems. The scars only make him look more pretty. One on his cheek, shoulder, fins, tail. It's clear he's used to a hard life.

Shiro likes to observe him most. He notices that the mer doesn't seem to like all the people watching him but...he literally has nowhere to go to hide from prying eyes. He's pretty aggressive and territorial. Shiro doesn't blame him at all. Shiro would be agitated in there too.

And then the mer starts to act...different. More intense. More territorial. More snarly. More...desperate...

Shiro sees as the other really acts weird. He misses a day here and there due to work and when he comes back, the mer has a strange collar on. And he's not acting like normal. He's in the corner, lying on his side. He's mostly asleep, which is odd. The mer hardly ever seems to sleep. And when he's not, he's uneasy, thrusting his hips in desperate needy circles.

Something isn't right. Shiro wants to find out what is going on. He'll come in at the least busiest time to visit the mer. The place is open 24/7 but it has waves of popularity. He quickly searches on his phone, noting that 3 am is usually the least packed time.

He'll be back soon.

And hopefully he can help, somehow...

Chapter Text

Keith is out of it.

He doesn't remember much of the past few...days?

He remembers trying to make his nest better. He remembers grabbing up every leafy or spongey material, packing it into a circle. He remembers digging for anything to add. He remembers his hand finding a strange rock?

Well, he's been using said rock for a while now. It's working far better than his fingers have. But it's also dirty and sharp and he's pretty sure he's repeatedly cut up his canal and probably has a fever now. And that's not caused by the ongoing heat.

He keens as he thrusts back down on the rock below him. He feels as the heat grows, as he grows slicker. At the same time, the smell of blood and distress puts him into an overwhelmed mode. He knows it's his own but his instincts scream that he's not safe and he needs to be bred and he wants his pack an-

Keith blinks in confusion as he notices that he's now against the glass wall. He glances upward, noting that familiar face watching him with concern and confusion. The man with the white bangs...

Wait...why is he here? Why is Keith pressing close like some...some needy half-breed needing to be taken right then and there? Well...that part is the heat. And he is a half-breed. But why this guy? He isn't scared like he should be. He hates people being this close. He despises people being this close to his territory. He-

Wait...he's drifting away?

Sure enough, Keith feels himself getting dragged back by the collar. It doesn't cut his air off or press hard into his throat. He whines pathetically despite the fact that his limbs loosen with that haziness he's been experiencing. He loses his grip on his rock, dropping it into the sandy dirt below him. His prehensile dick clings to it before the slickness of it makes him completely drop the rock. He whines again before growing agitated.

Soon enough, he's nearing the top of the tank. He's not surprised when that ring pole slides over his head, holding him in place as he breaches the surface. He's also not shocked when a second one joins on the other side or two latch onto each of his wrists. He doesn't have the energy to fight any of it so he just whines weakly before listening to the humans.

He's so out of it that he misses most of it. He understands humans and their language thanks to growing up near his pops. They obviously don't think he understands them, which is fair because most don't interact enough with humans to learn their language.

Something about bleeding and treatment tank and-

Keith jolts when something wraps around his tail. He growls in warning before trying to move away from the hold. Something else latches onto the other side, beginning to make him panic. He shakes his head before looking at his tail, seeing a padded cuff holding his limb in place. He looks around frantically, seeing that he's in a shallow tank, just big enough to fit into from head to tail. He's mostly in the water besides his head so he can breathe. Somehow, he can tell the collar is off even if another padded cuff holds his neck in place. Same goes for his wrists that are not far from his hips. He's about to inspect further when something presses along his birthing canal, sending heat through his body. He shivers slightly before glancing at said place.

One of the humans is looking it over with a worried frown, gloved hands pressing on his walls to open it more. He whimpers softly at the stimulation before trying to wiggle away or closer. At this point, either works for him. Some blood leaks into the water as well as some slick and probably other substances too. The woman presses her slim fingers in further, bring a small sound from Keith who tries to flex his hips some. His dick curls around her fingers, bringing them in closer to get that stubborn spot. Keith can't help the pained whine that leaves him as soon as the digits touch further within. It hurts now.

Probably from the rock...

"I fear he's got a rather nasty infection," the woman says to the others in the room, pulling her fingers away. Keith whines deeply at the loss as the woman glances his way with an understanding expression and to them with a frustrated and angry look, "Do you not understand mating cycles in some mers? He is in heat, for fuck's sake. He's an omega. He's going to try to soothe himself, including fucking himself on anything available. You should have offered him safe toys and better nesting supplies as well as some privacy."

He doesn't hear what the others have to say as heat curls around his stomach and hips. He just wants to be on his side and taken care of, preferably with his pack...or maybe even a certain human he barely knows...

He jolts roughly when something enters his canal again. Glancing at that area, he's unsure about the puffy white thing that the woman is offering. It smells weird and it also feels weird. But his dick curls around it before bringing it closer within.

He hisses quietly when it touches his walls. It stings a bit. But it soon settles down, leaving the area feeling less painful. He kind of likes the texture and so must his body for his tentacle clings to it all the way to the strange handle, pressing it further in.

It'll do. Probably better than his fingers. Way better than the rock.

"Is that a giant tampon?" One asks curiously.

"Sort of," the doctor speaks up, "It's made specifically for treating an injured mer who has severe internal injuries to their birthing canal. Usually after birth or a rough mating process. There's an numbing agent in it as well as a disinfectant. They also double as a good dildo for situations like this."

Keith presses it in closer, heat simmering through his veins as he eases it in and out some. He can see the blood sticking to it as well as some slick but it doesn't stop him from sliding it around as effectively as before.

"He's going to need one every four hours. I got a stash here for you to use. Just hand it over to him and he'll discard the old one. Keep him on the nutrients and antibiotics for the next week. Make sure you feed him his regular diet as well at least twice a day. This mer can't afford to lose any more weight or the infection will likely kill him," she scolds them before looking at Keith who whimpers, "Keep an eye on his canal. The bleeding should stop within the next few hours and the swelling and redness should go down gradually. If you notice anything change, send for me right away. I'll be back in a few days to check up on him regardless."

Keith blinks as the woman brushes her hand to his cheek. She's not wearing the gloves anymore as she smiles down at him softly.

"We'll get you on the mend," she says fondly before brushing her wrist over Keith's nose. A familiar scent lingers on her skin, leaving him feeling secure and confused. She smells like his pack and dad. But how? Keith's never met another hybrid with a human appearance. How does she know so much about mer care? Why does she smell like them? Who is she?

He whines deeply, limbs shaking roughly before he relaxes as much as he can in this small tank. He feels as his ears slip under the water, soothing him as everything quiets some.

He soon falls asleep...