Chapter Text
“Hey Eula… is there a possibility I could maybe um, borrow your taser?”
The blue haired woman turns her head to raise an eyebrow at Diluc. “Not the one issued to me by the FPD, no. I have my own I could lend you, but why exactly do you need one anyway?”
Diluc chews on his lower lip. “...No reason.”
Eula folds her arms, giving Diluc a suspicious look. Clearly, she isn’t convinced. “You don’t really peg me for the type that tases their marine specimens. Are you inhabiting some sort of dangerous sea life?”
“Something like that.” Diluc responds, his skin prickling while he eyes back at Eula’s own intimidating death stare.
“You do know you can get filed for animal abuse.”
“I think this is more of a self defense case…”
Eula exhales, turning around to tidy her paperwork. “Well, I don’t see why not. Your problems are your problems.” She leans over to pull out the drawer underneath her desk, revealing a taser small enough to fit in a pocket. “I’m not responsible for any of your injuries, okay?”
“Okay. Yes ma’am. Thank you--” Diluc breathes out, closing his eyes momentarily. Eula scares him. There’s something about her resting bitch face and forever cold aura that surrounds her, not to mention her position of deputy chief of police in the Favonius Police Department. Well-- there’s Jean, in a higher position of authority, but she just isn’t as intimidating as Miss Snow Queen Eula. He can’t help but start shaking in his boots (literally) when he talks to her. It also might be because she’s insanely attractive, with pale skin, sharp yet delicate features and, um, other attributes--
She’s just a friend to Diluc, anyway. He’s never really thought of the woman in a romantic or sexual way, and besides, she’s way out of his league. Oh- not to mention she’s also lesbian. And taken.
As Diluc swipes the taser from the drawer and slips it into his back pocket, Eula leans closer to him and lowers her voice. “Hey- asking this in a way that isn’t work related… is there any way you can get Amber to swing by my office today? I know she’s out on patrol, but it’s around your area and… well, if you see her, relay the message.”
Diluc frowns. “Oh. Yeah, yeah sure, of course.” He nods, straightening up. It’s not often Eula breaks out of her ‘work-mode’ during office hours, but of course, when it comes to Amber, Diluc isn’t sure what he expected anyway.
He jogs out of the Favonius Police Department, brisk walking straight towards the market. There’s a lot of things he needs to buy and even more items he needs to beg-borrow-steal from his very few friends today. It still does hurt, whenever he moves too suddenly or stretches past his limits— courtesy of the fish bastard. Luckily, Barbara, Jean’s younger sister and doctor intern, treated the wounds and told him it wasn’t that serious. Hopefully, he'll be fine after a few weeks.
As long as he doesn’t return to his lab and find all the tanks shattered and a missing abyssal fish, then everything is going to be just fine.
───
Diluc throws open the door, spinning around to lock it hastily behind him. He’d locked it while he was away, so hopefully that meant nobody had gone in or out. The last thing he needed was for any of his coworkers to be ripped apart brutally, by a fish no less. Addressing the specimen as a merman just made him feel more crazy than he already felt, but then again, fish was getting a little redundant, not to mention not at all biologically accurate.
With his many shopping bags, Diluc slowly makes his way over to a corner of the spacious lab, where a tank just about the width and length of a king size bed sits. It’s reinforced with steel plating along the sides and the bottom, so hopefully no disasters involving shattered glass would occur.
Diluc lets out a sigh of relief when he spots the merman squished inside the tank, his tail folded against the glass in a way that looks much too cramped. The thick iron chain locked around his neck is chained to the bottom of the tank, heavy enough that it sinks and drags the merman down as well (Diluc doesn’t want to mention how he even got his hands on that).
His heart twists. Even though Diluc knows the goddamned thing tried to eat him yesterday, it still hurts him to see a sea creature in such… bad conditions. The tank doesn’t have any plants or rocks or anything, really. It’s completely bare. It’s also much too small for the guy to even swim; turning around is a struggle already. It’s just cruel, but what choice does Diluc have? He feels like a horrible person, he really does, but it’s just that there’s no safe way to contain this thing in a way that won’t put his own life in danger. He’s had to cut costs and can’t afford a tank or enclosure large enough for the merman.
Well. He’s probably already harmed the poor thing enough. To get him out of the net and into the tank, Diluc had to spray the merman with a heavy amount of nitrous oxide to sedate him, then struggled for about thirty minutes before dumping him into the glass box.
Now, the merman lies at the bottom of the tank, tapping his claws against the floor. His gaze flits upwards when Diluc comes closer, giving him a happy wave.
“Hello there!” He grins widely (Diluc swears it’s just to show off his paper-shredder teeth). “It’s awfully cramped in this tiny box. Could you please let me out?”
Diluc glares at the merman while wrestling a box out of the plastic bag in his hands. “Stop. Just stop that--”
“Stop what?”
“Stop being so-- so human, it’s creepy…” Diluc mumbles, laying out the boxes onto the desk nearby. He keeps avoiding looking over at the tank because if he did, he’d just feel even more guilty. Honestly, Diluc would rather the merman have some sort of horrific face that didn’t resemble a person, or to not be sentient at all. Everything feels wrong, like he was keeping someone captive under the worst possible conditions. He can’t even begin to imagine how uncomfortable the merman feels in that stupidly cramped glass box.
Archons, why does Diluc have to care so much?
He shouldn’t. He really shouldn’t because the same fucking fish tried to claw his back out less than twenty-four hours ago, and here he is caring about his wellbeing.
“I think you would know by now that I’m not a human,” The merman eyes the boxes Diluc is unwrapping. “What’s that?”
“Food, because I’m not letting you eat my flesh,” Diluc says as he pulls out a slightly slimy anchovy and tries to think of how he’s going to feed this to the merman. He scoots over to the edge of the tank and very, very carefully, drops the anchovy inside.
The merman grabs it by the tail, sniffing it. “This doesn’t smell at all edible. It isn’t fresh.”
“Yeah, well, not all of us can afford fresh seafood, or have the time and ability to hunt them in the ocean.” Diluc continues to drop more anchovies inside the tank as the merman reluctantly eats them-- whole, of course, to add to the unsettling factor.
“What’s your name?” The merman asks after a few minutes of silence.
Diluc is caught off guard by that one. He hates himself more and more by the second, after all of this. “Don’t ask me that,” he replies sharply, perhaps a little bit more aggressive than he’d intended.
The merman pouts, it fucking pouts, Diluc didn’t even know mermaids were capable of that, that expression is extremely annoying. “Why not? Humans address each other by name as well, don’t they?”
Diluc tosses away the empty boxes of anchovies, having fed the merman (with a very very big appetite) all of the supply. “...Yeah, but you’re not-- human, you know, so…”
But even as he says it, the guilty feeling only increases. It’s like Diluc is ashamed for being so defensive about these things, for not even treating the merman like how he feels like he’s supposed to. Surely, because half of him is human, this isn’t right.
Then again, the same human half had also tried to kill him.
“Oh. Well, my name is Kaeya, thanks for asking.” The merman says after a moment, giving Diluc an unamused smile.
The attitude on this one--
“No. Just no, I can’t call you that. You aren’t even supposed to exist-- ”
“Ouch.”
“--not to mention I already feel bad for locking you up like that but I really can’t take my chances here when you want to fucking eat me! ”
“Is that really my fault? It’s sort of supposed to be in my diet. Whatever you’ve just fed me really doesn’t meet my nutrition standards.” The merman-- no, Kaeya because goddamnit, he has to have a name-- drawls.
“ Wh- You’re saying you’ve eaten a human before-- that’s disgusting, you’re-” Diluc exhales, barely managing to keep his cool. Something his therapist had mentioned to him-- he, unfortunately, had anger issues and an inability to keep his emotions under control. “You’re a monster. ” Diluc almost spits out the words, turning to Kaeya. “You’re a monster and that’s why you have to be chained to the bottom of this glass tank, and you’re going to stay like that for a while.”
Only now does Diluc realize that he’s raised his voice, his face feels slightly hotter and most likely appears a little flushed. No, shit-- he didn’t really mean to do that, it’s not in his nature, he’s not really like this all the time. The immediate regret hits him, and he glances away in embarrassment.
Think of what the therapist said, Diluc.
He knows what’s going on, because it happens really often. Diluc really isn’t mad at anyone else, he’s just frustrated at himself. Marine biologist, yet here he is, keeping a sea creature in captivity in a habitat that just isn’t suitable. It goes against all sorts of federal laws, not to mention going against Diluc’s own ideals. It’s probably tied to his past, but he knows that’s no excuse to get mad at a somewhat innocent fish.
He should apologize. Out of the corner of his eye, Diluc looks towards the merman.
Inside the glass tank, Kaeya just breaks out into an even wider grin. “You look beautiful when you get all heated up. Can I eat you?~”
Diluc inhales.
“You--”
───
“So let’s say hypothetically… if I had somehow pulled up, let’s say, a mermaid from the ocean, and this mermaid happens to be oh wow, cannibalistic… would it be fair to keep him locked up?”
Amber looks at Diluc like he’s gone mad. “Wow, I’d think you of all people would know that mermaids don’t exist.”
Diluc expected that to be the response, but the only reason why he bothered asking Amber first was because frankly, she seemed like the most likely to believe him. Among people like Eula, Jean and Lisa, she was kind of his only option. “I know, but I’m just saying, hypo--”
“Don’t worry about it! I believed in mermaids until I was sixteen. Remember how we used to go to the beach so often, and I’d sing at the top of my lungs towards the ocean? I thought I’d attract a mermaid, but instead I just scared away all the seagulls.” Amber says with a smile, giving Diluc a firm pat on the back. “Nothing to be ashamed of if you believe in them now! They are very beautiful.”
Diluc stares at the shorter brunette girl. He knows Amber already had a few screws loose, but now he is convinced she had no screws to begin with.
“I don’t mean that--”
“But I don’t think you should keep a mermaid locked up. They are just like every other sea creature, if not even more fantastical, no?” Amber twirls her baton around in one hand, sliding it back into the holder on her belt. “Mermaids are just as human as we are. That’s what’s so cool about them, isn’t it?” She beams at Diluc with the purest, most genuine smile that makes him feel even more guilty.
“Yeah. Yeah, you’re right.” Diluc nods, breathing out. “Oh hey, I visited the FPD earlier, and Eula wanted you to maybe drop by her office after your patrol’s over.”
“Really? Oh, of course! I better finish up, then--” Amber claps her hands together in excitement, already jogging off around the corner of the street. “See you later, Luc! Please find a girlfriend!” And with a wave, she’s gone.
Diluc wonders how Kaeya feels.
───
After hours of dilemma and Reddit consults, Diluc has finally decided to stay overnight at his lab, just to keep an eye on the merman. He knows that it essentially increases the risk of himself being attacked, but if he wants things to work out, then he has to build some sort of trust between him and the fish.
He should probably start off by using his actual name-- Kaeya. It’s definitely an interesting name, derived from a language that isn’t from Mondstadt. It makes Diluc wonder what kind of civilization he comes from. Strangely though, Kaeya and Diluc can communicate verbally just fine.
He drags his sizable duffle bag through the door, quickly shutting and locking it behind him. Everything he could ever need for a sleepover lasting a few weeks in his lab, of all places, is packed tightly into it. Diluc likes to think there’s a lot in there, but he’s just lying to himself. He is a really, really boring person with literally no interests outside of his job. The only item that makes him feel not as old as he actually is is his outdated Nintendo switch with like, three games on it. Other than that, his subconscious still lives in the era of flip phones and cassette tapes.
“Kaeya?” Diluc says quietly while he makes his way over to the back of his lab. The merman rolls over in his tank, offering Diluc the same sharp-toothed grin.
“Hello, beautiful,” Kaeya says. “You look so cute I could eat you right up~”
“Shut it,” Diluc replies offhandedly, then remembers what he’d wanted to say in the first place. He pulls over a rolling chair, sitting a small distance away from the tank. “Listen, I uh…” he begins, begrudgingly making eye contact with Kaeya, “I wanted to apologize for what I said earlier. You’re sort of… human too; you shouldn’t have been treated like that. I’m sorry.”
There’s a painfully long moment of silence, until to Diluc’s surprise, Kaeya begins to laugh. The action makes Diluc’s cheeks flare up in red again in embarrassment. This absolute bastard of a man-fish.
“What?” Diluc snaps, though it’s in more of a flustered way than irritated.
“Are all humans this endearing, or is it just you?” Kaeya somehow manages to look smug-- underwater and chained to the bottom of a glass box. “Will you tell me your name now?”
Diluc furrows his brows, beginning to unpack his duffel bag. “Flattery is not getting you anywhere near my flesh. It’s Diluc.” He then turns to stare straight at Kaeya “Also, we should make a deal. I know it’s really cramped in that tank, but I really didn’t have anything else with me at the time… so if you could kindly refrain from attacking me, I’ll do my best to get you a better place to live. I can’t let you back out into the ocean yet.” After a moment, he adds, “I’ll even try to get live fish for you or something.”
Kaeya seems to mull this over. “Sure! I don’t mind spending time with someone as delicious looking as you, Diluc~ ” He agrees rather easily, but the comment only makes Diluc sigh. There was no way to get rid of those creepy flesh-eating tendencies, but at least there was some sort of a contract between them.
The sun has already begun to set, bathing the lab in a warm, orangey glow. Diluc plans to have dinner, answer a few emails and maybe… start to study Kaeya. There’s still so much he wants to learn about the species.
He sits on the rolling office chair and unwraps his takeout. It’s grown slightly soggy and cold, but it’s nothing he isn’t used to. He spears the xiao long bao with a plastic fork, bringing it to his mouth. Just when he’s closed his lips around it, Kaeya notices.
“What’re you eating?”
“It’s Liyuen food,” Diluc replies while chewing, carefully tilting the box (wooden, because of course he refused the styrofoam one and brought his own) downwards so Kaeya can see. There are about six small dumplings inside, of the cheapest variety sold at the Wanmin Restaurant chain a few blocks away. They might be hardly nutritious enough for an actual meal, but compared to what Diluc usually eats, it’s gourmet. After a moment of hesitation, he asks, “Want to try?”
Kaeya nods enthusiastically, catching the bao in his mouth-- a bit like an actual fish-- when Diluc drops it into the tank. His expression morphs into that of distaste.
“It’s so… bland. ”
“Yeah, because human flesh must be so flavorful.” Diluc responds dryly, eating another. While he finishes his food, his gaze flits over Kaeya’s form. He’s actually… not bad. Don’t get Diluc wrong, his standards aren’t that low, nor is he into fish or men, but Kaeya has an excellent physique. Diluc comes to a halt at his tail, seeing something he hadn’t noticed before.
There’s a large scar, except it doesn’t seem to be a scar and instead a wound. It’s bright red and irritated, the scales around it shredded and barely hanging on. Diluc frowns through his food, putting the box and fork down.
“You’re injured?”
Kaeya appears confused, then to the best of his ability, twists his tail so that the gash comes into his view. “Oh. Well, I guess I am! I guess I must have forgotten.”
Diluc bites the inside of his cheek, but his body moves before his mind does-- standing up and grabbing the medical supplies he keeps in a corner of his lab, just in case. How does he go about this? He’s never really treated injuries on… fish, before. But considering this guy was a man-fish , it couldn’t be too far from wrapping up a normal cut. Hopefully.
“D’you mind if I…” Diluc gestures vaguely, bandages and antiseptic cream in his hands. Kaeya answers by ungracefully sticking his tail out of the tank and draping it over the side, open wound above the waterline. Diluc cautiously inches forward, putting a hand very, very gingerly on the tail.
Last time, it sort of bitchslapped his face, but now that Diluc runs his fingers over the iridescent, dark scales, they feel smooth when rubbed one way. He rips his gaze away from the intricate patterns and instead turns them towards the wound. Diluc dabs at the gash with a damp towel, cleaning and gently brushing away the torn scales that cling onto skin.
Kaeya seems to study him intensely with that singular, cold blue eye, which only makes Diluc’s skin prickle-- isn’t he supposed to be the one studying the other? He doesn’t really mind this opportunity to dress up Kaeya’s wound, though. It gave him an excuse to get up close and personal with that horrifically long fish tail of his.
“How did you get this anyway?” Diluc asks, just to break the painfully heavy tension between the two, because of course, whenever he’s alone with someone else he always manages to fuck a conversation up. Even when he’s with a fucking fish.
Kaeya frowns, a small bubble floating upwards from his mouth and breaking at the surface. “Can’t recall, honestly. When you’ve got a tail as long as mine, and as many scars as I’ve gotten, do small injuries like this really matter?”
“I don’t know if I’d call it small…” Diluc mumbles, beginning to apply the cream. “But won’t anyone notice you’ve gone missing? I’m surprised you’re this eager to stay captive.”
“I’m nobody important,” Kaeya says offhandedly. “I’m only this willing because I’ve found myself such an interesting, adorable snack right in front of me. Will you please let me have a taste?”
Diluc wants to slap the stupid, smug smirk right off Kaeya’s face.
“Well, thanks… but no.” He sighs, wrapping the gash carefully with gauze and securing it in place. It seems to stay closed like that, so thankfully, Diluc doesn’t have to give a pathetic attempt at sewing stitches. He’s nowhere near a professional at things like this, but he also can’t exactly ask Barbara to patch up a glorified fish’s tail. Everything still feels a bit surreal to him, like how he’s got an actual merman locked away in his lab. Right in front of him, actually. He brought Kaeya to his lab to learn more about his species, that was all. Technically, it was related to his job, and he wasn’t working on any particular project at the moment.
“You have a family, then? Even humans must come from somewhere.” It’s an innocent question, coming from Kaeya, but the words feel like a needle pricking Diluc’s heart.
“I did. Not anymore.” Diluc answers plainly, avoiding eye contact with the merman. It all happened when he was so young; he’d never given it much thought when he grew older. With some assistance of a therapist and being on medication, things that happened in the past tended to stay in the past.
“You lost them?”
Diluc doesn’t really know. He knows he lost his father to the ocean, but instead of remembering the details, the only image his mind has retained is a huge, looming, tentacle-like sea monster made of the waves, ripping and tearing everything in its path. That had included his father. Later on, he’d learnt that it was most likely just a crutch his mind had used back then to soften the blow. There weren’t such things as sea monsters, everyone told him.
It was strange though-- instead of being terrified of the ocean, Diluc couldn’t help but return to it again and again. It felt like he was searching for the monster; instead of fear he’d felt fascination.
Shortly after, his mother passed away since she couldn’t handle the grief of losing her husband. She would’ve died anyway, though-- the doctors found a brain tumor as well.
Diluc hadn’t even reached middle school.
So yeah, his entire life has pretty much been a shit show.
“It’s not important to me,” Diluc doesn’t spare those thoughts any emotion anymore. Something wet and thin brushes his forearm. He glances over-- a semi-transparent pelvic fin lies there, almost in a consoling way. Like it’s Kaeya’s way of comforting another. He is vaguely surprised the merman knows how emotions even work, because sometimes Diluc sure doesn’t. His red eyes flit upwards to meet Kaeya’s blue.
It’s not half as bad, though.