Like A Wave

* I'm a shitty tagger, but here goes my attempt
* It's me, so there will be angst
* I promise a happy ending
* Krbk (duh)
* Bottom Kiri (though he may fuck Baku at some point, idk)
* Mpreg (I can't resist krbk kids )
* Kiri has a tentadick
* Experimentation

* A brief explanation of mermaid genitalia; all mers can have babies so there are no 'males' or 'females' in that sense.
* All mers have the same genitalia.
*The baby making hole will only be referred to as a 'hole'. NO afab terms.

“Watch your step here, Doctor.” Says the uniformed male – some military prick that walks around like he’s got a stick up his ass – as he leads Dr. Katsuki Bakugou through the bowels of an old Navy ship. It’s used for research, supposedly.

At least, that’s what he was told on the chopper ride here after being dragged from his slumber by two military officers pounding on his door at half passed one in the morning.

He’s worked with them before. Not often, but a few times over the years.

Enough to know that he hates it. Enough to know that they only ever drag him in when whatever poor helpless creature was unfortunate enough to be caught by them is on the brink of death, and not even their doctors can fix it.

Not that that’s too surprising though. They’re not like him. They’re not even in the same league as him. He’s a specialist. The best in his field.

A veterinarian whose specific area of expertise is in caring for marine life. The military has been trying to recruit him for years to come work with them at their marine research facility, but he always turns them down.

He’s not interested in just barely keeping something alive long enough for them to complete their tests on it before letting it die. That’s not why he became a vet. And now, thankfully, they’ve stopped asking.

They just call him in when they desperately need him, and reluctantly, he comes because he can’t in good conscience leave something to suffer, when there’s a chance he could’ve done something to help it. Even if that something is just to make it’s passing a little less painful.

He usually goes to one of their land bases though. Never out here. But according to the little he’s been told, this particular case is special. Top secret.

All of the cases he’s been brought out on for them are, but this one especially so considering the amount of paperwork he had to fill out promising that he wouldn’t speak a word about it to anyone.

Supposedly, it’s something new. A new species of fish or some shit that came up out of the depths, and they’re not quite ready to share it with the world just yet. Hence their research on it currently being conducted out here in the middle of the Pacific.

“It’s just through here.”

Katsuki nods, already mentally preparing himself. He wouldn’t necessarily call himself a very soft person, but that still doesn’t mean he likes seeing anything suffer.

He’s a vet for fuck sake. He just…it’s easier if he doesn’t try to set his expectations for a good outcome too high.

As it would turn out though, nothing could prepare him for what he was about to see when they open that door.

It’s a man. A man lying strapped to a table with heavy metal restraints. “The fuck?” he asks, pausing momentarily. His first thought is that this must be some kind of stupid joke, because he doesn’t work on humans, he works on animals.

But then he looks at the definitely infected gash that’s been poorly stitched across the man’s hip, and what appear to be burns or a rash of some kind – possibly from the infection – across his torso, and legs, and crawling up his neck towards his cheek, +

and he knows there’s no way this is a joke.

One, because these people have about as much humor as a dead fish, and two…well, it’s awful hard to fake injuries like this. “You need a doctor.” He says, shaking his head.

“That’s why you’re here.” Says the man closest to him. He’s the head of their research team. He introduced himself when Katsuki came on board, but he can’t quite remember what he said his name was.

“Yeah, but I don’t do people.” He tells them, watching the injured man on the table turn his head weakly to stare in his direction.

Fuck, is this even legal? He looks half out of his mind with fever. He needs a fucking hospital, and he needs one fast.

“I assure you, doctor, despite what he may appear to be in this form, this creature is not human. Get a bit closer and see for yourself.”

Katsuki's brows scrunch, half in annoyance and half in curiosity as he steps closer to the edge of the metal table, quietly wondering what the hell they could’ve been doing to this guy to make them say he’s no longer human. “I swear, if this is a fucking joke –“

“It’s not a joke. Just look.”

The restrained man gives a weak lurch in his direction, baring his teeth and letting out a threatening hiss as Katsuki gets closer, making him pause.

Those are certainly not human teeth. At least, not any like he’s ever seen before. They look like something that belong in the mouth of a fucking shark.

And the burns, or the rash, or whatever the fuck it is…it sparkles. It glitters in the light kind of like…well, kind of like fish scales, which is surprisingly exactly what the strange red patches seem to be.

Really dried out scales on his arms, and legs, and face, and…everywhere. Little red patches mixed in with soft human skin, going down into legs that look half fused together. Kind of like they couldn’t decide whether to be legs or one large fin.

“What the fuck did you people do to this guy?” Katsuki asks, instantly pissed as he turns to face the director again. “How the fuck is this kind of experimentation even legal?”

There has to be someone he can call, right? They can’t just get away with this. They can’t just experiment on a fucking person like this. Can they?

“Dr. Bakugou, please calm down.”

Calm down?! Do they have any fucking idea who they’re talking to?! Behind him, the restrained man is getting more and more agitated. Hissing, and growling, and thrashing in his bindings.

Katsuki shakes his head again. “You people are fucking nuts. I’m leaving, and I’m taking him with me.” He says, reaching into his back pocket to get his cell phone so he can call someone out here to come get them.

Someone with some human medical expertise that can hopefully at least try to help the poor guy they’ve been experimenting on.

Only…his phone isn’t there. It’s upstairs. Upstairs in that room they first brought him to. Fuck!

The head researcher frowns. “I’m really sorry about this, Doctor. But unfortunately, we can’t let you do that.” He says as two uniformed soldiers step up on either side of Bakugou’s body to grab his arms.

“What? Oi! What the fuck do you people think you’re doing?” he snaps, his heart beginning to race as he tries to break their hold.

“Once again, I’m very sorry, but we can’t let you leave.”

“Can’t let me…what the fuck do you mean? You can’t just fucking –“ he cuts off abruptly when he notices a woman in a white lab coat approaching him with what he can already assume is a sedative. “Stop!” he shouts, fighting harder. “STOP! You can’t just –“

And that’s all he remembers before he feels the sharp prick of a needle in his arm and his vision fades out into black.

***

When Katsuki wakes again, he’s lying on the floor, and the room is empty. No more researchers. No more assholes in military uniforms. Just him and their half dead botched experiment. Fuck.

He sighs, trying to keep a level head as he climbs to his feet to take a quick personal inventory.

His limbs feel like they’re filled with lead, and his head it still kind of fuzzy from the drugs - not to mention, also throbbing, so he’s pretty sure he must have hit it at some point – but all in all, he seems to be alright.

He’s just really pissed off and wants to go the fuck home. //See if I ever help these pricks again.// He grumbles under his breath as he tries the door.

As expected, it’s locked. Because why the fuck wouldn’t they lock him in here after drugging him to keep him from leaving in the first place. It’s just common sense.

They brought him here to do a job. He didn’t do that job, and now here's his punishment.

Clearly, these assholes just don’t understand the fact that he still can’t fucking help this guy though. He’s a fucking vet, and they can lock him in here as long as they want, but his credentials aren’t just going to miraculously change.

He pounds his fist against the door. “Oi! Assholes! The longer we keep playing these games, the less chance Frankenstein’s monster over there has of surviving, so let me the fuck out!”

“You will be released, Mr. Bakugou, once you’ve done your job, and not a moment sooner.” A voice crackles through a speaker in the room's ceiling.

Katsuki jumps, not expecting it, as the man on the table let’s out another warning hiss. There must be cameras in the room. Someone watching them. “And if I do nothing? If I just let nature take its course?” he asks. At this point, it may be the more humane option.

“Then I assure you that just as no one will ever find this ship unless we want them to, they will never find your body.” It’s someone else who speaks that time. A voice Katsuki doesn’t recognize. One that sends a chill down his spine and right into his core.

And just as quickly as he opens his mouth to respond, he closes it again. He may be brash and a little bit reckless at times, but he’s not an idiot. And trying to call their bluff right now in his current situation would definitely make him an idiot.

“Fucking fine. I’ll do what I can, but it’s not on me if he doesn’t make it.” He tells them, fighting the keep the slight edge of fear out of his tone as he goes to snatch the fish man’s chart up off the counter to get a better idea of what he might be dealing with.

Because right now, he doesn’t have the slightest clue, but he’s quickly realizing that not figuring it out might have higher consequences than he’s willing to pay.

~Eijirou’s POV~

Eijirou was always warned against interacting with humans. When he was little his moms would tell him stories about their ancestors and their dealings with the humans. Dealings that ended in bloodshed, and sent their people into hiding.

‘Why momma?’ he’d asked once. ‘Why do we have to hide?’

'Because humans are greedy, my little price.’ She told him. ‘And they will always try to take more than they’re given.’

But still, Eijirou didn’t quite take her warning as seriously as he should have. And as he grew, he became more and more curious about the mysterious two leggeds on the land above.

He would explore shipwrecks, and hoard secret troves of the odd treasures he found there. And for a while that was enough. But eventually, he wanted more. Just a little peek. Just one.

But one turned into two, and two turned into three, and before he knew it, he was visiting the surface every day. Sometimes it was to watch the humans.

He never got close enough that any of them could see him, but he’d watch them run through the sand, and splash in the shallow waters, and listen to them laugh.

And other times he'd just swim to the surface to feel the warmth of the sun’s rays against his scales. That was always far from the human lands though. Far out into the ocean where only huge floating ships roamed.

One of which had a huge, trailing web below it; skimming through the water and picking up fish.

He’d only wanted to free them. He'd only wanted to get just a little bit closer to the strange shimmering web.

But then he’d gotten swept up in it too, and before he even knew what was happening, he was being pulled upwards and farther out of the water than he’d ever been before.

Which is when the pain started. Terrible ripping pain that felt like he was being torn in two. Like his scales were stretching and shredding apart. It was blinding. Pain unlike anything he’d ever felt before.

And then he hit the deck, and so began his journey with the humans, and his sudden realization that they were every bit as horrible as his mothers had warned.

And he’s certain this one is no different with his sand colored hair - that oddly reminds him of a sea urchin - and deep, angry scowl. He eyes him suspiciously; giving a threatening hiss when he comes to stand nearer to him.

A few weeks ago he’d have given anything to see a human this close. But now…

Now he knows his mothers were right. Humans are bad. Greedy. They take and they steal what doesn’t belong to them. Like him. He doesn’t belong to them. He belongs in the sea. But they still took him.

Now, he doesn’t know where he is. He called for help – for his mothers – on the first few days when they put him in their 'tank'. He even tried to swim back to them. But the water here has invisible walls and he couldn’t. He could barely even turn around.

But now, he’d even take that over this. Even if the water isn’t clean enough. Even if it reeks of his own fear, and sadness, and despair. Even if it reeks of pain. He needs the water to heal. To fully be able to transform again. And he needs food.

/Real/ food so his body has the strength to do it.

Because they took his strength. The strange humans in white. They took it when they made him change forms over and over and over again until he couldn’t anymore. Until he was stuck like this. Stuck between both.

They took it when they saw him lying in the bottom of his tank as a bad thing – not just his body trying to conserve energy - and pulled him back out again.

They took it when they brought him in here and tried to force him to eat their rotting fish again even when he’s tried to show them he can’t.

He’s tried – starvation got the better of him and he didn’t have a choice – but all it’s done is make him sicker and weaker. And right now he can’t risk getting any weaker than he already is. Especially with the new human.

He can feel his fear. He can feel it growing. He can smell the bitterness of it, and hear the increase of his heart rate as his scowl deepens at the glowing box in his hands. The humans like that box. Especially their leader.

He spends much of his time watching and poking at it with his fingers.

“Oi! Is this for real?” the sandy haired man shouts upward, drawing another warning hiss from Eijirou.

In his two-legged form, he can tolerate their voices, but stuck like this their loudness makes his ears ring and hurt.

No response comes as the sandy haired man sets the glowing box aside and stares at him. He’s trying to look tough. Trying to hide his fear. But Eijirou can still feel it. Can still smell it. Even as the man hesitantly reaches towards him.

Eijirou tries to wriggle away. Tries hissing louder and baring his teeth. And at first it works. The man pulls back just the slightest, but then the look on his face hardens and he starts reaching again. Faster this time.

“I’m trying to fucking help you, Shitty Fish. Or what ever the fuck you are…” He says.

And then suddenly the pressure that’s been pressing down on his stomach is gone, and a little bit of him can start to move again.

/Start./ He eyes the man suspiciously; their gaze holding each other for a moment before the man reaches out again to release one of his arms.

Eijirou doesn’t hiss that time.

Or the time after that as the sandy haired man reaches over him to carefully release his other wrist, and then both of his legs. He doesn’t trust the man – or quite what he’s doing – but he wants to be free, and that means not scaring him or making him move away.

But then he stops; taking another moment to just stare. There’s only the restraint left. The one around his neck. And if the man takes that off, he’ll be free. So why is he waiting?

Eijirou reaches up to clumsily pull at it; trying to communicate that he wants that one off too.

But the sandy haired man seems hesitant. Maybe even more hesitant than he was when he released the first of the restraints. “If I let you go, you gonna attack me?”

Eijirou just stares at him, unsure of what to do besides pull at the bar around his neck again.

The sandy haired man sighs; pinching the bridge of his nose as he shakes his head. “You’re a fucking fish and I’m talking to you like you can understand me.” He says, taking a step back as he runs one of his hands back through his hair.

His stress is increasing again. Eijirou can smell the sharp bitterness of it seeping into the air around them, making his nose wrinkle in disgust. He /can/ understand him though.

He’s a fast learner. All of his kind are and he’s been around these humans for weeks. He just hasn’t figured out how to get his own voice to work outside of the water yet.

“Of fucking course you’re gonna attack me.” The sand haired man says, beginning to pace.

But he’s wrong. Eijirou wouldn’t. He just wants to be free. He just wants to go back home!

“They wouldn’t just restrain you like that if you weren’t –“

“N-o.” Eijirou forces out; feeling like he’s trying to push the words out past his lips from the very tip of his tail fin. “N-o h-ur-t.”

~Katsuki’s POV~

He’s losing his mind. He has to be. The panic settling deep inside him at being trapped in this room with…with…with whatever the fuck the half fish thing is has to be fucking with his head, right? Because he swears he just heard that thing try to talk to him.

And a few minutes ago when he thought it was human, that probably wouldn’t have bothered him too much. But now…fuck. If what he just read is to be believed, then they pulled this God damned thing out of the fucking ocean.

And no matter how strangely 'human' it looks, fish aren’t supposed to fucking talk.

Hence, the only logical answer to him thinking he heard it speak is that he’s losing his mind.

//But if it’s a fish, how the fuck is it breathing?// He asks himself. //And why the fuck does its fin look more like a pair of partially scaled, fused legs than an actual fin?//

There’s a name that keeps popping into his head, but he can’t bring himself to admit even to himself that that’s what he’s looking at right now. It’s supposed to be the shit of fairytales. Children’s books. They’re not supposed to actually exist.

And yet…he can think of no better name to call it as it stares up at him with red uncertain eyes, still pulling at the metal restraint around its throat.

“Uh-ff. Uh-ff.” It repeats, which Katsuki doesn’t want to acknowledge sounds pretty fucking close to 'off' for something he’s stilling trying to deny is speaking to him.

It’s just his subconscious though, right? Just the part of him that doesn’t like seeing anything – animal or human – being caged or restrained. He’s not really hearing words; he just thinks he does.

But still…taking that last restraint off might be risky, despite the confidence he had in his decision a few seconds ago. He is trapped in a room with this thing, after all.

So how smart is he to free it when he has no clue how fucking strong it is and no way to defend himself if it tries to kill him?

“Uh-ff.” it tries again, pulling harder with a look in its eyes that could almost be taken for pleading.

Katsuki sighs; rubbing a hand over his face. “Fuck it.” He says, shaking his head as he opens the last of the restraints. With the way it looks he doubts it has the strength left in it to kill him even if it wanted to. And if he’s wrong…well, he really fucking hopes he’s not.

The moment it’s loose, the fish flips its poorly fused tailfin with such force it knocks the table, itself, and a whole array of tools from a nearby tray onto the floor, giving Katsuki barely enough time to dive out of the way before he’s hit by any of it.

“Fucking Shitty Fish! You could’ve - ” He starts, but cuts himself off the moment he’s able to flip over again after everything has settled and sees the poor thing curling itself into the farthest corner of the room, trembling.

Fuck. Katsuki wouldn’t exactly call himself a person who often feels a lot of strong emotions – anger probably being the only exception – but something about the state of this poor creature hurts his heart in a way he’s never felt before.

Or maybe that’s just because he hit his chest on the floor…

Either way though, he can’t just sit here and do nothing.

As far as he can tell, this thing seems to be much more scared of him than he is of it at the moment – though he’ll never admit he was ever scared to another soul for as long as he lives – so he might as well try to capitalize on that and do his damn job.

As he gets up off the floor and starts gathering a few supplies from the drawers – bandages, a stethoscope, a bag of saline – he’s aware of the fish creature’s eyes following him. Almost like a predator following its prey. Should he take a weapon?

Maybe. But would he even be fast enough to use it if he needed it? Judging by the way it flipped off that table, probably not.

So, he leaves the scalpel behind and just hopes that his reflexes alone will be enough to save him again if this thing isn’t as cooperative to his helping as he thinks it will be.

“Alright, Shitty Fish, you’d better not fucking attack me, or I ain’t doing shit for you.” He says as he picks up the tray and starts moving towards it.

Because even if he doesn’t want to admit that it was speaking to him earlier, there’s a part of him that at least has to acknowledge that it can probably understand him even if he wants to deny that too.

The closer he gets though, he’s surprised to find it isn’t quite as combative as he thought it would be based on its level of fear. It’s still trembling, and it’s trying to push into the corner deeper, +

but it’s not hissing or threatening to attack in any way like it was when it was strapped to the table. It’s just scared.

So, he sets his tray down and slowly crouches to its level – it’ll be faster to get up if he needs to if he’s not sitting – to examine it. It doesn’t appear to have hurt itself any – not that he can tell – in the fall, but he won’t know for sure until it uncurls.

Which he doubts it…he…Katsuki’s pretty certain his initial assumption was right and it’s a male…will do until he feels comfortable. And he won’t feel comfortable without a good fucking reason after whatever the fuck these military pricks have done to him.

Making sure the traumatized fish-man is watching, Katsuki puts on a pair of gloves and start to soak a few bandages in saline.

The scaled parts of the fish-man's skin are obviously dried out, and while a quick fix to that would obviously be just to put him in water, right now some saline soaked bandages are all he has access to, so they’ll have to do.

Once he’s finished, he picks one up and slowly moves it towards the fish-man's shoulder where the scaling looks the worst.

As expected, he tries to pull away, eying Katsuki warily as he keeps moving the bandage closer.

“Keep still, Shitty Fish, I’m gonna make you better.” He tells him. And he means it. He’s got no clue how – he doesn’t even really know what the hell he’s dealing with yet – +

but these military shits are not gonna kill what may be the only creature of its kind because of negligence and stupidity. Not while he’s got anything to say about it, that’s for fucking sure.

“H-urt.” The fish-man says, continuing to try to pull away. “H-urt!”

“No, it fucking won’t. Just –“ Katsuki finally just closes the gap between them and drops the bandage in place, not worrying about how it goes on, just that it’s mostly where he wants it to be.

The fish-man reacts with a strange, strangled shriek like he’s been burned – which is admittedly startling, and momentarily makes Katsuki wonder if he was wrong – before he settles again when he realizes it actually didn’t hurt him.

He cocks his head, looking with confusion at the bandage haphazardly placed on his shoulder as he reaches up slowly to poke at it with his finger.

“See? It didn’t fucking hurt, did it?” Katsuki asks.

The fish-man pauses a moment, then slowly shakes his head. “Mm-ore.”

Christ, he’s actually having a fucking conversation with a damn fish, isn’t he?

Katsuki picks up the next soaked bandage and puts it over the rest of the exposed skin on the fish man's shoulder, swatting his partly scaled hand away when to reaches up to touch it again.

The fish-man flinches, jerking back, and hissing in warning.

“Oh shut it, ya Shitty Fish.” Katsuki rolls his eyes, surprisingly less wary of him now that he’s up close and they’ve had a chance to interact a bit.

As far as he can tell, while this creature – he downright refuses to call it a fucking merman – seems to have the capability to tear him apart faster than he can blink, it doesn’t want to. Not even when he’s got him backed into a corner like this.

His instinct is still to pull away from painful stimuli rather than attacking which is why Katsuki assumes every scientist on his ship isn’t dead yet. And why he himself wasn’t killed the moment he released this thing from his restraints.

So, not only is he a shitty fish, but he’s a pretty shitty predator too. No wonder he got caught.

“Sh-it-ty ff-ish.” The fish man says; testing the words on his tongue.

Katsuki smirks. “Yeah, that’s you.” He says; starting to lay more of the gauze strips down on the fish man’s arm. This one is covered – mostly – in scales, but the other one still seems to be mostly human looking and covered in skin.

Clearly he’s stuck between a more human-like form and his natural fish state – still not calling him a merman – but Katsuki can’t help but be curious about what he would look like fully transformed.

Especially since his scales – though they’re kind of a dull-ish grey currently – do seem to have some kind of pigment to them that they’re currently lacking.

“N-ot sh-itty f-ish.” The fish-man suddenly says, drawing his attention.

“What?”

“Not sh-itty fish.” He repeats, clearer this time. “Ay-je-row.”

At first, Katsuki doesn’t quite get it. He’s clearly trying to say something, but it’s not a work in any language he’s ever heard. Then the fish man taps his chest and repeats it a second time and it suddenly Dawn’s on him.

It’s not a fucking word, it’s a name! “Eijirou? Is that your name?”

The fish man’s face splits in a wide, toothy excited grin; nodding happily. “Eijirou.”

Interesting…fish man has a name. He’s not sure why he never considered it a possibility before, but it really should’ve been obvious that something human-like and capable of speech would probably have something to call himself by.

Katsuki takes a break from the gauze to point to himself. “Katsuki.”

“K-aught-sk-ee…Kaught-skee…Katsuki. Katsuki!” he exclaims excitedly; clearly pleased with himself. “Katsuki.” He pokes Katsuki’s chest, then his own. “Eijirou.”

“Yeah. Katsuki and Eijirou. You got it.”

The fish man – Eijirou – spends the next few minutes repeating Katsuki’s name under his breath, like a child who just learned a new word, while Bakugou keeps putting gauze over his scales.

It’s a quick fix for now, and it seems to be working, but he can’t help but wonder how long they’re gonna be in here. Because what Eijirou really needs, is a tank.

A tank – the ocean would be better, but he doubts he can convince any of these pricks to set him free - and some -

Eijirou stops speaking; his stomach seeming to grumble right on cue with Katsuki’s thoughts. “Hungry.” He frowns.

Food, he thinks to himself as he stares at the outline of ribs visible under Eijirou’s skin. This fish really needs some fucking food.

He looks up towards the ceiling and the camera in the corner. He could ask them – he knows they’re still watching – but he doubts they’ll risk opening the door to give him anything even if he did. They’re pretty stupid, but they’re not /that/ stupid.

So, for now he’s just gonna have to hope some IV fluids will do the trick to liven Eijirou up enough that he can get these fuckers to open the door and give him better access to what he really needs.

“Katsuki feed Eijirou?”

“Yeah, yeah. I’m gonna get you something. Don’t worry.” He says. He just hopes Eijirou doesn’t freak out too bad when he sees the needle…

***

As it turns out, Eijirou freaking out over the needle isn’t even something he has to worry about, because the fucking thing won’t even pierce his skin. Not even a little.

“The fuck are you made of?” Katsuki asks; frustrated when the fourth needle in a row snaps in half the second he presses down.

At first, he thought maybe they just had some wimpy ass needles, but now that he’s actually had a change to inspect the fish-man's skin a little closer – and broken three more - it’s clear that this is just how he’s built.

The needles aren’t too weak, his skin is just too fucking hard. Which probably explains why he wasn’t given any kind of fluids before this. Doesn’t explain why the fuck they didn’t try a feeding tube though.

It wouldn’t have been comfortable, or simple, but with the way they had Eijirou restrained earlier, it at least would’ve been possible and preferable to letting him starve.

Eijirou’s stomach grumbles again. “Hungry.”

“I know, alright? Just give me a damn minute.” He snaps. This isn’t gonna fucking work. “Oi! Assholes!” he shouts at the camera; standing and striding up to face it.

He still really doubts they’re gonna help, but he’s at least got to try something. “Can we get some fuckin’ fish in here or something? He’s fucking starving to death!”

There’s no answer – he doubted there would be – but he knows they heard him. Now all they have left to do is wait and see if they get what they want.

“Katsuki good.” Eijirou says when he comes to sit by him again, and resumes covering his lower half in gauze. “Eijirou like Katsuki.”

“Yeah, you’re not so bad yourself, for a Shitty Fish.”

~Eijirou’s POV~

Eijirou sits quietly while he watches Katsuki tending to his poorly fused tail fin; laying long wet stripe over it to sooth the burn of the air. His scales aren’t meant to be left to dry out this badly. They can stand being exposed for brief periods, but definitely not this long.

That’s why his body is built to change, he assumes. So his scales won’t dry out when he’s on land. He wonders why his mothers never told him? Why they kept it a secret from him that he could take on a second form?

Maybe it was because they were worried that something exactly like this would happen. Maybe they were just trying to keep him safe.

He wishes now that he’d listened to all of those warnings they’d given him. They were right. Humans are terrible.

All except this one. This one with his sandy hair and piercing red eyes. He likes this human. He’s a good human. The most manly of all the humans Eijirou has ever met.

And he smells delicious.

Not in an edible kind of way. Eijirou would never eat a human. They would taste awful. No, he smells good in a very /different/ kind of way. A way Eijirou has never smelled anyone before; mer or human.

A way that makes his insides tingle where he’s definitely never felt them tingle before, and his belly pool with heat.

Suddenly the door pops open; startling him as a bucket is kicked inside the room with them before the door immediately slams shut again.

He hisses warningly; baring his teeth as he sniffs the air. It’s fish. Dead fish. He can smell their rancid aroma wafting from inside the bucket even from across the room.

He crinkles his nose, watching Katsuki retrieve the bucket and bring it closer to him.

“What’s the face for, Shitty Scales? It’s your breakfast.”

Eijirou frowns. Now he’s Shitty /Scales/? He doesn’t understand what this word – this 'shitty' – means, but it must be a good thing, right?

Katsuki keeps using it in reference to him, and this time to his scales – which are quite beautiful when properly hydrated – so it can’t be bad, can it? Katsuki wouldn’t do that. He’s good. Eijirou…trusts him.

So maybe he can give these fish a try. Maybe this time they won’t be as bad as they were last time because Katsuki was the one to give them to him. Maybe this time they’ll be 'shitty'.

Slowly, Eijirou reaches his hand into the bucket and plucks out one of the fish from amongst the frozen chunks of water; bringing it up to his face and giving it a long, deep sniff.

He wrinkles his nose again. Dead. Definitely dead. For a few days now at least. But maybe…

He sticks his tongue out; giving the dead fish a tentative lick…. nope. Nope he definitely can’t eat this. It’ll make him sick! When he chucks it across the room to get the scent of it as far away from himself as possible though, he earns a disapproving look.

“The fuck did you do that for?” Katsuki asks; sounding angry.

“Bad.”

“Yeah, you are bad.”

Eijirou pouts. That’s not what he meant. “Bad /fish/.” He clarifies; pointing to the bucket.

“They’re not bad. That shit looks human grade!”

Eijirou doesn’t know what that means, but he doesn’t bother trying to figure it out. He just reaches into the bucket, pulls out another fish, and points. “Dead.”

“Yeah, that’s how it’s fucking supposed to be!” Katsuki says, clearly not getting the point.

“Dead fish bad!” Eijirou tells him, pointing harder.

And that time, finally it seems to click. “You need them alive to eat them?”

Eijirou nods, his face splitting in a brilliant smile again; ecstatic to finally be understood. “Yes! Yes! Alive!” he exclaims, gesturing with his hand to mimic their wiggling.

Food! He’s finally going to get food! He’s so excited as he watches Katsuki cross the room to shout at the ceiling again that he flips his tailfin; unintentionally dislodging most of the wet strips from their place and completely wrecking all of Katsuki’s hard work.

Oops…

***

“Now don’t fuckin’ move.” Katsuki tells him crossly as he reseats the final few pieces of gauze – that’s what they’re called, apparently – on Eijirou’s tail.

“I mean it. I’m not fixing this shit again.”

Eijirou nods; a look of determination on his face as he tries to will himself to not move so much as a muscle again so he won’t ruin all of Katsuki’s hard work.

This is the second time he’s had to reset the gauze.

The first was after he got excited about the prospect of food, and the second - this time - was because the ship started to move and he got scared. He hasn’t felt the ship move in a long time, and it’s a weird feeling being that he’s actually sitting still.

“Wh-ere going?”

“I don’t know.” Katsuki tells him with a shake of his head.

But he can tell the sandy haired man is uneasy again, and this time it’s not because of him, which is worrying. Does he think they’re going somewhere bad?

Before he has a chance to contemplate it any further, the door opens up and two men come in pointing long, oddly large sticks. “Come with us.”

Eijirou lets out a warning hiss, trying to remember not to move even though he really wants to.

Katsuki looks back at him, then to the other men. “I’m not leaving him alone in here. He needs to be watched.”

“Don’t worry, he’s coming too.”

There's a bit of arguing that happens after that which is too hard to follow, but he understands that the gist of it is, they want to strap him back to that horrible table again, and Katsuki doesn’t want them to.

Which is greatly appreciated, because Eijirou definitely doesn’t want that to happen either.

Finally, Katsuki stops arguing and comes back over to him. “I’m gonna carry you, so don’t move around too much, alright?”

Eijirou hesitates a second. Carry? He’s never heard that word before, but Katsuki’s not done anything to hurt him yet, so he can trust that this probably won’t hurt him either…right?

He nods, watching as he puts an arm under his fin and another behind his shoulders and lifts him from the flood.

Eijirou scrambles, giving a little screech when he feels the gauze start to slip. He wasn’t supposed to move!

“It’s fuckin’ fine, just stop squirming.” Katsuki tells him, seeming to strain as he tries to hold on.

Eijirou stops, frowning as he watches a piece of the gauze slip off onto the floor. “Where going?” he asks again; wrapping his arms around Katsuki’s neck to keep himself steady as they begin to move, following the other men from the room.

“I don’t know.” Katsuki tells him; still obviously straining under his weight. “But don’t worry. I’m sure it’ll be fine.”

Eijirou nods, sniffing the air as he tries to see if he can smell anything familiar now that they’re out of the room. But he can’t. All he can smell is the strange, bitter scent of the ship mixed in with the saltiness of the ocean. Nothing new.

So he tries to do his best to keep calm and trust that everything will be fine. That his new human companion – his Katsuki – is right. And if he’s not, then he trusts he will keep him safe. He did tell him he would, after all.

The longer they walk though, the more Eijirou starts to recognize. This…this is a path he’s been taken on before. It goes back to what the humans call their 'lab'. The place they study him from. The place where they keep his tank.

Maybe that’s where they’re taking him? He hopes so. Being back in the water would feel good on his scales, even if he’s not really sure he can fully finish transforming yet. But it’s fine. It’ll happen eventually, they just need to not take him out again until it does.

And he's sure Katsuki will stop them if they try. He seems to already understand the importance of the water in helping him heal, so he’ll want to keep Eijirou in the water just as much as Eijirou wants to be there. Maybe if he’s lucky, Katsuki will even get in too!

Then they can finally talk. Really talk. He’s still learning how to do it outside of the water, so it’s kinda hard to get what he wants to say across. But inside the water is –

“In here.” the man leading them says; gesturing towards one of the doors and interrupting his thoughts.

He was right! They are taking him back to their lab! He can see his tank! He almost starts squirming with excitement, but then he remembers that Katsuki told him not to move, so he doesn’t.

“The fuck is that?” he hears Katsuki ask, and though he’s pretty sure the question isn’t for him, he answers it anyway.

“Tank!”

“It’s where we keep him.” The other man responds.

“Where you – are you fucking kidding me? It’s barely big enough for him to turn around!”

That’s true…it is kinda small, but at least it’s water. When he first got here, they did he didn’t even have that. He just had a strange cave they kept him in that made his skin feel raw and his newly formed leg bones ache.

So, in comparison, the tank is a much better place to be.

“It’s the largest we can have on board.” The other man says, leading them up onto the small platform above his tank.

The humans like to be up here. They like to watch him. And Eijirou thinks it’s funny to watch them too because of the odd way the water distorts their faces.

“In.” Eijirou points.

Katsuki sighs. He’s not happy about something. Is it the water?

“In.” Eijirou points again, harder this time. Maybe if he came too he would see it wasn’t that bad?

He doesn’t bother trying to point for a third time when Katsuki ignores him to keep fighting with the people in white when they come to join them. He just gives a single hard flip of his tailfin and sends the both of them toppling into the water.

~Katsuki’s POV~

At first, Katsuki can’t quite make sense of what the fuck just happened. One second he’s on the platform, arguing about the sorry excuse for a tank they’re keeping Eijirou in, and the next he’s drowning.

The tank…fuck, Eijirou must have pulled him into the fucking tank!

He tries to push off the bottom to swim back up, but something’s keeping him in place.

Eijirou. The fucking fish has got his arms wrapped around his waist holding him under the water! Almost instantly, his survival instincts take over and he starts thrashing, trying to break free.

But no matter how hard he tries, he can’t. He can’t fucking get free, and if he doesn’t do so soon, he’s gonna fucking drown!

“Dude, stop fighting. It’s okay. Just give it a minute and your body will change.”

Change? Oh shit, does this fucker not understand that there is no changing for him? He can’t breathe under water! But how the hell is he supposed to communicate that when trying to wrestle himself free from Eijirou’s arms isn’t fucking working?!

He probably wouldn’t even understand if he tried to make the universal signal that he can’t fucking breathe by grabbing at his own throat, because Eijirou is a god-damned fish! He probably doesn’t even understand the concept of drowning!

So, he just does the only thing he can do, and keeps fighting him; hoping that eventually that’ll get the point across and he’ll let him go. But what if he doesn’t? Is he just doomed to drown here?

Those fucking scientists are still up on the platform above them, but they don’t seem to be all the worried about the fact that he’s dying. They’re just fucking watching like this is another one of their experiments!

And that’s when it hits him. They really aren’t worried. If he dies, he dies. They really don’t care. They don’t care, because they were never planning on letting him off this ship alive in the first place.

If he wasn’t drowning right now, he’d probably laugh at how stupid he’s been. Of course, they’re not planning on letting him live. Yes, he’s worked on secret projects for them before, and he’s always been discreet about it, but this…this is an entirely different situation.

Eijirou is the very first of his kind that humans have ever seen, as far as he knows. They can’t risk sending him back to land after this. They can’t trust him with a secret this big.

They were always going to kill him, right now they just have the opportunity to let Eijirou do it for them, and they’re taking it.

But if they think Bakugou fucking Katsuki is gonna go down without a fight…well, they’re about to learn a very important lesson. He’s a survivor and he’s not gonna be taken out this easy.

So, he grabs ahold of Eijirou’s arm closest to his mouth and bites down hard. Hard enough to taste blood. Hard enough to make the – he just needs to finally admit this is a fucking mer – goes rigid and finally loosens his grip enough for Katsuki to get free.

Fuck! He did it! He can’t believe that actually fucking worked!

Obviously, the last thing he wanted to do is inflict more pain on the poor mer than he’s already experienced – especially since he didn’t seem to understand that what he was doing was wrong – +

but it did the trick, and that first breath of air again when he breaks the surface feels fucking glorious.

He chokes and sputters, doing his best to grip the edge of the tank to keep himself afloat while he catches his breath. “Thanks for all the fucking help.” He gasps sarcastically.

The head scientist just shrugs, seeming unfazed. “You seemed to be handling him fine on your own.”

Katsuki would like to send him for a little swim as well for that comment, but he keeps himself in check.

They don’t need to know that he knows their plan for him. Not yet. It’s better if they just think he’s still oblivious. That’s what’ll make whatever his counter attack is all the more surprising and effective.

Getting himself up onto the deck again after he’s caught his breath isn’t any easier of an ordeal, since he still doesn’t get any help until finally one of the solder’s – the one that walks like he’s got a stick up his ass – helps drag him up the final few inches.

Fuck! That was hard. Katsuki considers himself someone who’s in pretty good shape – he has to be in his line of work – but he also doesn’t usually god swimming fully clothed, or have to drag his entire bodyweight up without a ladder after he’s finished.

“Thanks.” He tells the soldier – Iida, according to the name embroidered on his uniform – as he lies on the deck, catching his breath again.

Below, he can hear the sound of Eijirou finally resurfacing, but he can’t force himself to move any more to know whether or not he’s okay. He’s pretty sure he is though. It’s not like a bite to the arm has ever killed anyone before.

Especially not someone with as hard of skin as Eijirou has.

Speaking of which...how the fuck did he just bite him hard enough to draw blood, when before his skin was hard enough to break needles?

Is his skin weaker in water? That doesn’t make a whole lot of sense, but then again, a lot about this whole situation doesn’t.

The only thing he’s sure of, is that he will have to tend to that bite wound after he’s had a chance to rest. After all he’s already been through, the last thing the poor mer needs right now is a fucking infection.

***

After a while, finally Eijirou is brought his live fish and allowed to each for the first time in what must be weeks judging by how quickly the water in his tank turns red from his feeding.

Which is…admittedly a little terrifying to watch, considering that he eats like a fucking savage animal. But it’s good. He’s glad Eijirou’s getting to eat, and he looks much more lively after he’s finished.

Only…he’s frowning.

“The fucks the matter now?” Katsuki asks, sitting on the edge of the deck watching him. They’re the only ones here now. Not completely – there are still people in the lab – but he’s the only one still by the tank.

He’d thought they were finally done with all the pouting though. Eijirou had been…strange when he finally emerged after their little scuffle under the water, but he got over it quickly.

Katsuki just explained that he couldn’t change forms and then the scaly little shit had gone all sad on him, begging for forgiveness for almost killing him.

Which Katsuki forgave him for, obviously.

It’s not Eijirou’s fault that nobody explained to him that the changing of forms wasn’t a universal thing across species. And that was the end of it. The assholes running this place came in with his food after that, and everything was fine again.

Until now, at least…

Eijirou looks up at him, pouting despite the healthy shine his skin has taken on. “I didn’t save you any.” He says, lowering his gaze to the carnage left behind in the water. “And you’re hungry too.”