Chapter Text
Lan Xichen knew about the merfolk, of course.
You couldn't study the ocean without taking at least a semester on the underwater dwellers, and while Lan Xichen was far past his college years, he still kept up to date on research papers. The mer were a fiercely reclusive civilization, and even the rare few who interacted with humans never gave much insight into the species as a whole.
Well. Except maybe the one that Wangji had met as a boy, but he refused to tell Lan Xichen anything, because the mer had made him promise and because his brother was awful.
(Wangji was not awful. Even thinking it made Lan Xichen feel guilty.)
Still, even knowing of the mer, and having been a marine biologist for over a decade, Lan Xichen had not expected to actually meet one.
"And what does this do?" the mer asked, playing with Lan Xichen's watch, which was thankfully waterproof and also apparently easy to steal.
"It keeps track of time," he replied, sitting down on the concrete next to the quarantine pool. When the mer had popped up at the side of his boat and asked for help he had not screamed, definitely, but in the time it took him and his team to get the injured mer back to their facilities for treatment, at least his heart rate had gone down a little bit.
The mer had introduced himself as Huaisang from the Qinghe-Nie pod--and Lan Xichen hadn't even known the merfolk had named, distinct factions--and requested help with a shredded caudal fin.
"How are you feeling?" he asked.
Huaisang hummed, a low vibrating sound that was almost like a purr. He continued to poke and prod at the watch, turning the dials and looking pleased when the hands moved accordingly.
"Better," he replied cheerfully, wiggling his tail in the water to demonstrate. He had vertical fins like a shark, and scales that glittered golden green; the anatomy didn't match that of other mer that had been documented, but then none of them had been the same either. One spotted off the coast of India had a brightly colored tail that resembled a lionfish; another seen near Australia had looked like a dolphin's.
According to Wangji, the one he met had long flowing fins like a betta, inky black limned in vibrant red.
Huaisang's certainly had taken a beating--he'd needed a long row of stitches to close a gash in the dorsal part of his caudal fin, another few on his ventral, and the tip at the bottom had been hacked roughly off. It looked like propeller damage--as if he had gotten too close to a boat, like other ocean mammals sometimes did.
They usually had the disadvantage of not knowing any better, though. And by the keen look in the mer's eyes, Lan Xichen did not think Huaisang was at all unintelligent.
"I don't know how long it takes for you to heal," he said apologetically, "So I can't say how long the stitches need to stay in. We can take you back to the ocean now, if you like, and you can come back when they need removing."
Huaisang waved one webbed hand.
"I'll just stay here until I'm ready," he decided, like he wasn't taking up an entire research tank, like he knew they wouldn't deny him.
(They wouldn't. They absolutely would not. Lan Xichen was prepared to take the mer to his own bathtub if Huaisang wanted to stay on land longer, he refused to lose this chance to speak with one of the merfolk.
Also Huaisang was rather endearing, in a wide-eyed, excitable kid kind of a way, and the simple delight he took in playing with human things reminded Lan Xichen of Wangji when he was a child.)
"Is there anything we can do to make you more comfortable?" he asked. "I'm afraid we don't really know much about..."
'Your species' would sound incredibly rude, wouldn't it?
"Well, I usually eat three or four fish a day, about this size." Huaisang held his hands apart by about a foot. "Anything local, doesn't really matter. But--"
And here the mer's eyes gleamed.
"--I would be more than happy to try whatever human food you think might work. And then I can tell you more about myself!"
Lan Xichen stared at Huaisang's bright smile and understood, suddenly, what the legends meant when they spoke of sirens.
"...let me get some takeout menus."
Lan Xichen very quickly became the most envied researcher in the facility.
"Why does he only want to talk to you?" Lan Jingyi complained, depositing a massive bag of takeout onto Lan Xichen's desk. It was dim sum, this time, a bunch of different boxes stacked on top of each other, and it smelled amazing.
"I don't know," Lan Xichen admitted. He saved the notes he'd been working on, leaning back from his computer and stretching the ache out of his shoulders. "Maybe because I was the one who treated him? It might be an attachment thing."
Lan Jingyi grunted, unconvinced, and fished a crumpled receipt out of his pocket to drop into Lan Xichen's lap. The teen was working as an intern over the summer, Lan Xichen happily putting in a good word for his distant cousin, but he felt bad that Lan Jingyi was mostly relegated to fetch jobs.
"Did you get something for yourself?" he asked. "It's on the department's tab."
"I'm not dumb enough to turn down free food," Lan Jingyi sniffed, pulling out a couple of the boxes and a pair of chopsticks.
After a moment of hesitation he ducked his head and dug into his pocket again, coming up with a cheap plastic yo-yo.
"I got this from one of the gacha machines," he muttered, tossing it next to the receipt. "I thought he might like it."
Lan Xichen smiled.
Aside from inhaling food with his delicate, razor-sharp teeth, Huaisang had also proven to be absolutely insatiable when it came to all things human. He had eventually given back Lan Xichen's watch, but only after trading it for a fidget cube from one of the other researchers. That was swapped out for the metal Hanayama puzzles Lan Xichen kept in his desk, and those for a swiss army knife, and that for a rattle drum.
Eventually someone had just brought in a box of random things (half of them children's toys, conveniently waterproof), and watching one of the mysterious merfolk play delightedly with a wind-up submarine had to be one of the best things Lan Xichen had witnessed in his life, ever.
"I'm sure he'll like it."
Jingyi nodded and scuttled off, clutching his food like the perpetually-hungry teenager that he was, and Lan Xichen picked up the bag to head to the quarantine tank.
He found Huaisang drawing on the floor to the side of the pool. There was a compact mirror propped up next to him, and the likeness of himself was actually pretty detailed, for all that it was done on concrete with bathtub markers.
"We don't have this kind of art down there," Huaisang said as he approached, not even looking up. "Most of it's carvings and sculpture, stuff that can withstand the currents. The things you have, like paint and canvas, where you can add depth simply because the layers have time to dry..."
He glanced at Lan Xichen with a small, wistful smile.
"It's really nice up here, you know?"
Lan Xichen settled down in a patch of dry area, contemplating the young mer as he unpacked lunch. He opened up boxes and set them and the yo-yo in a neat row along the side of the pool, waiting until Huaisang floated over before he spoke.
"I don't know if it's safe for you to stay," he said quietly, honestly, and felt his heart clench at the disappointed--but not surprised--expression that stole over Huaisang's features.
Despite the fact that he'd gathered an enormous amount of data over the past couple days, despite the fact that he would love to keep Huaisang as a guest for as long as the mer wanted--Lan Xichen was not a fool. The staff at the facility were fiercely loyal, but there was only so long you could keep secret that they had one of the merfolk in residence. The media frenzy it would create aside, laws regarding the mer were ambiguous due to their rare interactions with humans, and there would always be greedy people in the world looking to claim a rarity for themselves.
Lan Xichen hadn't even reported Huaisang's presence to his administrative superiors; he'd registered him into the system as an injured dolphin. Even if the board didn't have the kind of people that would force Huaisang into scientific research against his will, the mysticism around mer was still widespread, and anything to do with merfolk could sell for thousands of dollars.
It was far, far too tempting for the ones in charge of their underfunded lab.
Huaisang sighed, poking dispiritedly through the boxes of dim sum. He bit into a piece of pork bao, and that at least seemed to cheer him up a bit.
"How long do you think I have?"
"Another week, at most."
Huaisang nodded and continued sampling from the assorted boxes, his mood lightening as he discovered the har gow and fried squid. He picked up the yo-yo and unspooled the string, chewing absently as it got tangled around the tips of his fingers.
"I think that'll be long enough," he said.
Lan Xichen tilted his head curiously.
Long enough to heal? Long enough to sate his curiosity of the human world? Whatever had compelled Huaisang to break from the merfolk's conventional policy of isolation, it didn't seem that he was satisfied with its progress.
Lan Xichen didn't ask, but he did hope that the young mer could find at least some kind of fulfillment in his visit to the surface.
Two nights later, he woke to singing.
He'd started sleeping in his office over the past few days, partly to be on hand in case Huaisang needed anything and partly because he just had so much information to organize. There was a futon in the back that was supposed to be for all-nighters, but he usually fell asleep at his desk anyway.
Lan Xichen blinked blearily as he sat back in his chair, pulling a sticky note off his cheek as his brain stirred sluggishly to awareness.
The song was wordless--or, at least, it wasn't in any kind of human tongue. It echoed hauntingly through the empty halls, longing and questioning and curious. It made Lan Xichen taste salt on his tongue; made his breath catch in as if it had been stolen. He shivered as he pulled up the security feeds on his computer, flipping to the quarantine tanks.
Huaisang had his hands planted firmly on the edge of the pool, most of his upper body lifted out of the water. His head was thrown back, long hair a dark ribbon draped down his spine and over his dorsal fins. He swayed gently as he sang, eyes closed, a small smile on his lips.
It was painfully beautiful, and for a long while Lan Xichen just sat there with his eyes closed, letting the sound wash over him, letting it resonate in his bones like whalesong.
And then, abruptly, it ended.
A quiet sigh escaped Lan Xichen's lungs; he took a moment to center himself before opening his eyes. There was an indescribable feeling in his heart, and he rubbed his chest for a moment before looking back at the security feeds to see if there was a reason Huaisang had stopped.
Five seconds later he was bolting out of his office at a full-tilt run.
The quarantine pools weren't that far away. It was unlikely something would happen before he got there. But there had been someone standing at the edge of Huaisang's tank, and as the only person who should be at the facility, Lan Xichen didn't dare waste a moment getting there.
He burst through the doors, nearly braining himself as his shoes slipped across wet concrete.
"Huaisang!"
Lan Xichen grabbed the nearest weapon-shaped object and bounded over to the pool, standing opposite the tall figure, who was far too close to the young mer for comfort.
"Huaisang, come over here, quick."
"You know his name?"
Lan Xichen paused, frowning at the man, who was...painfully attractive, actually.
He had long braided black hair and fierce features, his brows furrowed as he glanced between Lan Xichen and Huaisang, standing with his arms crossed over his--bare--chest with absolutely no indication of alarm. There was a gossamer-thin vest over his broad shoulders, a strand of shells and shark teeth hanging from his neck, and his pants had the same texture as seal skin. His feet were bare.
Lan Xichen felt a sudden, hysterical foreboding rise in his chest.
"Huaisang," the man said, "Why does the human know your name?"
Lan Xichen dropped the squeegee.
"Brother," Huaisang wheedled, in the same tone of voice he'd used to convince Lan Xichen to order deep-fried rice cakes, "It would be rude not to! Of course I told him my name."
"Brother," Lan Xichen repeated numbly.
"You shouldn't even be here in the first place!" Huaisang's brother snapped. "Do you know how hard it's been to convince Zonghui not to banish himself to the abyss for losing track of you? Why did you take so long to call me?"
Ah. The singing.
"I was having fun," Huaisang admitted without a hint of repentance. His brother's eye twitched. "Besides, look who I found!"
Huaisang swam over to Lan Xichen, who tried to take a hasty step backward because he was not prepared to get in the middle of a merfolk family dispute, but the young mer grabbed his wrist in a merciless grip and dragged him along the side of the pool toward his brother.
Up close, the man--the mer--was even more stunning, and Lan Xichen could see the family resemblance. He could also see the way he went pale--and then, bewilderingly, red.
"Huaisang," the mer hissed.
Still holding onto his wrist, Huaisang tugged until Lan Xichen looked down at him, beaming bright and guileless in a way that Lan Xichen now knew was an absolute filthy lie.
"Mingjue's been in love with you for ages."
Lan Xichen's brain, very inconveniently, decided to stop working.
"Huaisang!" Mingjue roared, lunging for his brother, who squeaked and darted hastily away.
Lan Xichen watched dumbly as Mingjue hit the water, his skin shimmering, his lower body melting into scarred fins and glittering green scales that cut through the water like a knife. With only a few powerful strokes of his tail he had the younger mer pinned against the side of the pool, a hand--now webbed and taloned--covering Huaisang's mouth.
"I am going to kill you," Mingjue seethed. "I am going to destroy all of your shells and sculptures and feed you to the abyss-damned shrimp--"
"Um," Lan Xichen said.
Mingjue froze. Huaisang wiggled under his brother's body, making muffled sounds against his palm, and didn't look the least bit concerned about the death threats.
"I...have questions," Lan Xichen admitted plaintively.
Mingjue closed his eyes with the kind of resigned expression that reminded Lan Xichen of when Wangji was particularly exhausted from his boyfriend's poor decision-making.
"Very well. You may ask."
How do you turn into a human? Lan Xichen's brain screamed. How did no one ever discover this? Can all mer do it? Are there limitations? Restrictions? Is it painful? How does that even work when it comes to the conservation of mass?
"I don't remember meeting you," is what he said instead.
Mingjue grimaced. Huaisang squirmed around and this time was allowed to escape, ducking under his brother's half-hearted swat to drift back in Lan Xichen's direction.
"Do you remember the school of sharks you helped in the cove just south of here?" he asked.
Lan Xichen blinked.
He did, actually: it was the first large-scale rescue operation he participated in after moving into town to work at the facility. Coastal flooding caused by heavy storms had given the sharks access to a usually-inaccessible bay, and after the water levels went back to normal, they'd gotten trapped behind the shoals. A few had been injured, and the threat displays when anyone went close to them had locals debating if they should just be culled instead of relocated.
There had been one in particular of concern: a larger male shark that the others had clearly been protecting, but in the end was actually the first to allow the rescue team to approach.
Lan Xichen looked at Mingjue, who was very studiously not looking at him.
"That was you?" he blurted.
"He was escorting them to our hunting grounds when they got caught in the storm," Huaisang supplied happily, swimming over to his stash of snack foods on the edge of the pool. He rummaged around before coming up with a bag of kit-kats, which he proceeded to examine with the same amount of focus in opening that Lan Xichen saw in bored cephalopods.
"Were they all...?"
Huaisang pointedly turned his back, focusing further on the wrappers that Lan Xichen had seen him open quite easily just a day ago.
Mingjue huffed and shot his brother a mutinous look.
"No," he said after a few stubborn moments of silence. "I was the only mer. Most of us can't take other forms like that."
"Big brother is special," Huaisang piped up, casting a beaming smile over his shoulder before returning to his treats. Mingjue snorted.
"You could do it if you worked on your cultivation and actually studied."
But Mingjue did look at Lan Xichen, then, and whatever he saw on his face made him duck his head.
"You were very gentle," he said, quiet and honest. "And your hands were kind."
"I... Thank you," Lan Xichen breathed. He sank to the ground with what was probably an entirely ungraceful thud, scooting as close as he could to the pool, his shoes hanging just over the water.
And he held his breath when, hesitantly, Mingjue swam nearer.
"Usually humans see us as mysteries to be solved," the mer said, studying Lan Xichen closely, as if he was drinking in every inch of him, "Or creatures to be examined. Our interactions with you are...stilted."
Lan Xichen glanced away. He wouldn't take on the misdeeds of others, but he knew full well the complicated--and often tragic--interactions that humans had with merfolk. He wasn't responsible but he still felt it, a shame that soured his stomach.
Cool fingers brushed against his jaw.
He snapped his head up, wide-eyed, staring at Mingjue's face now so close. The mer offered him a wry smile, his hand--no longer webbed, no longer taloned--cupping Lan Xichen's cheek in his palm.
"Most of our lesser kin are seen as merely food, or sport," Mingjue said quietly. "But you took care of them. You saw them injured and faced their teeth and you still wanted to help. I could not leave them to their deaths--but neither could you."
Lan Xichen swallowed hard and stubbornly ignored the wetness that gathered in the corners of his eyes. There was a distinction between hoping you made a difference--tending to injured animals, letting them go back to the wild, telling yourself to believe they would be fine--and having it confirmed. Having someone with authority tell you that, yes, you did something good. You helped.
He didn't realize the tears were falling until Mingjue brushed them away, a gentle expression softening the mer's face.
"Look," he murmured, balancing the salty droplets on his fingers. "You've always had the sea in you."
Lan Xichen hiccuped a laugh, and leaned down to rest their foreheads together, and smiled.
"Yes," he said, "I suppose I have."