Archive of Our Own ^beta

Chapter Text

Stiles disappears on a Sunday. Monday night, Derek dreams of a pool that smells like the ocean.

 -

The Sheriff is almost out of his mind with worry and frustration. Practically all cases are put on hold as he siphons department resources into finding his son. As days pass, nearly everyone’s hope diminishes to finding some sign of Stiles, be it his Jeep or his phone. Only the Sheriff and Scott refuse to believe he’s anything but alive.

Or so they say, at the very least. It’s clear to anyone who knows them both that they’re slowly giving way to resignation. They won’t stop searching - they’ll never stop searching - but the longer they go without finding anything the harder it is to convince themselves that they’re not looking for a corpse. Chris makes calls to less than reputable sources. Lydia flips the pages of Stiles’ books near her ear for hours on end listening a voice, just a whisper of confirmation or negation. She says she hears nothing but rolling waves of white noise.

Derek doesn’t tell her it’s the sound of the wind near the shore. Near Stiles’ shore.

-

He’s being held just barely above the water’s surface, limbs heavy and deadened. Panic leeches into his veins and speeds up his heart. He spares a moment, just one brief second, to wonder if Stiles can feel how terrified he is. The boy’s arms are wrapped tightly around him, legs kicking against his useless ones as he tries to keep them both afloat.

Water sloshes into Derek’s mouth when he attempts to say something, but instead of the chemical taste and smell of chlorine, salt explodes onto his tongue and he swears he can feel sand on his skin.

-

The dreams leave him feeling disoriented, as if his own senses are turning against him without rhyme or reason. He’s promised to meet up with Scott today; they’re going to pick up where they left off searching for Stiles’ scent near Beacon Hills city limits. But when Derek steps out of his apartment and breathes in deep, all he can smell is the ocean. He starts driving, but he doesn’t end up meeting Scott. Instead he finds himself roaming southwest, taking roads that draw him closer to the coast.

He doesn’t stop driving until the sun hangs low in the sky.

Why this particular beach, Derek doesn’t know. But as he pulls up and walks down to the where the waves lap the sand he can’t help but scan the water intently. Without taking his eyes away from it, he pulls off his shoes and his socks, stepping into the tide until his ankles are covered. For minutes he stands there, senses fully turned to the ocean in front of him. He has no idea what he’s looking for, but sees and hears nothing beyond the ambient sounds of the beach itself. There’s nothing here.

Derek shakes his head and sighs. What the hell is he doing? He’s got multiple voicemails and texts on his phone from Scott asking where he is, what has happened. He’s wasted an entire day he could have been helping with the search chasing phantom instincts. The Sheriff is counting on them, has gone so far as to beg them to help him find his son, and Derek is taking trips to the beach. Angry with himself, Derek retreats from the tide to his shoes, trying desperately to come up with a reason for his own sudden disappearance.

And then he sees movement out of the corner of his eye, hears the displacement of water just before he turns his head. He sees nothing but a circle of rock formations close to the cliff many yards away. If it weren’t for the ripples of water that move contrary to the waves, Derek would have been certain he was imagining things.

But the longer he stares the more he is convinced that he sees something moving under the water’s surface. Whatever it is moves within the circle of rocks, blocking his view. Derek spares a glance to his shoes before wading back into the water, the rolling of the waves masking his slow advancement. When he reaches the first rock, he anchors himself by placing his hand against it, apprehensive for reasons unknown.

When he peers around the rock, he sees Stiles, naked as far as he can tell, leaning back against the stone with his eyes closed. At first Derek is almost certain he isn’t breathing; his body is as still as Derek’s ever seen it, eyes unmoving beneath their lids and chest barely expanding when taking in a breath. Derek find himself unable to move further, too busy taking in Stiles’ wet hair and calm face. Perhaps, if he were more attentive, he might have noticed Stiles’ hands, still large and long-fingered, but now discolored with nails much longer than usual.

He is, however, fully aware of the inky black eyes that are now staring back at him instead of the familiar brown. Before he can process this or even think to move, Stiles throws himself off of the stone and into the water, a bright tail matching the sunset flailing water back in Derek’s face.

-

Scott is angry with him. Derek understands, though. He lets Scott yell at him, push him by his chest, and assert that Derek doesn’t care. It’s not true, but Scott is hurting, pain and desperation and fear for his best friend hanging over him like the weight of the world. It makes his shoulders sag and tinges his scent with a deep sadness and longing.

The Sheriff says nothing during this, merely continues to stare at the phone held loosely in his hands, no doubt reading the last text Stiles sent to him so many days ago.

Making dinner 2nite so don’t stay 2 long after ur shift. Love u!

-

Derek returns to the deserted beach under false pretenses; Scott thinks he’s seeking aid from a pack a county over. He’s prepared this time, stripping down in the sand until he’s in nothing but a pair of trunks he bought on the way here. He wades out to the circled rock formation, pulling himself up onto one of them and waits. The sun rests on the surface of the water in the horizon and Derek begins to feel anxious when nothing disturbs the area around him. Standing, he gazes out onto the waves before bringing his hands to his mouth to call out Stiles’ name.

He feels like an idiot, standing half-naked on a rock in the middle the tide, calling to someone who isn’t there. Daylight is fading fast, and even with his enhanced sight, he has very little hope of seeing much out there when night falls. It would just be his luck that he frightened the boy off yesterday, missing any chance of bringing him back. Despite feeling this way, he stays until the sun is no longer visible and color drains from the sky. He hears nothing but the wind and the waves, calming sounds that do nothing but drag his heart down to his stomach.

Suddenly he feels the lightest of touches against one of his calves. Spinning quickly around, he sees a hand disappear over the side of the rock. Without thinking, Derek jumps off and into the water, throwing his arms out blindly and gripping tightly when his hand finds a limb. His head breaks the surface of the water and he takes a gasping breath before something slithers around his waist and strong hands pull him back under.

The same arms that once held him up are now trying to drag him under.

Eyes flashing and claws extending, Derek grips the tail that’s trying its hardest to crush his ribs and pulls at it. There’s a surprising amount of resistance and Derek fears in the back of his mind that he may not make it back to the surface. Unwisely, he opens his mouth, using what force he can muster to let out a howl that seems nothing more than a onslaught of precious air bubbling up in between them. Surprisingly, the tail lets go and the arms retract. Lungs spasming painfully within his chest, Derek kicks himself up to the surface, coughing and breathing as deeply as he can. He swims quickly to waist-deep water, reveling in the feeling of his feet on something resembling solid ground. He doesn’t continue all the way back to shore, though, instead turning back and searching for Stiles.

Derek finds him half-hiding behind one of the rocks, watching him intently, body poised to act at a moment’s notice. Derek doesn’t care.

"Stiles, what the hell?" he shouts incredulously. Stiles blinks his inky eyes at him, brow forwarding and lips forming a frown. There’s confusion etched in every line of him and Derek feels his anger dissipate. "Stiles?" The boy tilts his head. "Do you know who I am?" Derek asks. Stiles says nothing, merely watches him for a moment longer before diving back under the water and swimming away.

-

Derek doesn’t like lying to Scott, but he knows he could use some semblance of good news. He tells him that they now have an extra pack looking for his friend. Scott isn’t relieved so much as he is appreciative, seemingly renewed in his determination to continue his search. The Sheriff places a warm hand on Derek’s shoulder and thanks him.

When Derek sleeps that night he tries to focus on the scent of salt water and ignore the guilt he feels underneath his ribs.

-

He’s back at the beach the very next day some time around noon. Despite the agreeable hour, there’s still no one around. He hears the occasional car pass on the highway, but there are no beach goers around for at least half a mile left or right of this secluded spot. He doesn’t know why this is, but he’s thankful for it.

This time, he doesn’t have to wait long for Stiles to show up. He keeps his distance though, watching Derek with only half of his face breaching the water. Derek does his best to look nonthreatening, swimming slowly out to the rocks and climbing on top of one. Pulling his knees up and resting his arms on top of them, he plans to do this as he would with any other cautious animal; stay as still as possible and let it come to him.

Derek tries to hide his smile as he watches Stiles’ natural curiosity get the better of him. Slowly but surely, Stiles begins to swim toward him. Derek takes in the brightly colored tail that trails behind him, fascinated by how the scales merge seamlessly into skin at his hips, though continuing to follow the path of his spine. Derek can’t help but think it’s beautiful and he’s ashamed.

Stiles stops just short of him, still watching Derek carefully. After a long pause where neither of them moves, Stiles reaches a hand out of the water and touches Derek’s foot. Raising an eyebrow, Derek adjusts his position, causing Stiles to back up a few feet. Derek holds his hands out as a sign of peace before throwing his legs over the edge of the rock and into the water. He sits and waits as Stiles approaches him again, running his finger from Derek’s knee down to his ankle, and Derek takes a calming breath at the touch. He watches as confusion spreads over Stiles’ face again before he looks over his shoulder back to his own tail. There’s frustration in his movements when he splashes his tail against the water a couple of time. With something like envy, Stiles turns back to touch Derek’s leg again.

"You used to have them too," Derek says. Startled, Stiles looks up at him. "Do you remember that?"

There’s another pause before Stiles tentatively nods, as if unsure. Derek feels a small sense of relief, and perhaps a significant amount of surprise, that Stiles still understands him.

"How did this happen, Stiles? What did this to you?"

He reaches out - he doesn’t know what for; to touch Stiles’ shoulder, maybe to brush aside the wet lock of hair on his forehead - but Stiles is gone in a flash of iridescent scales, swimming away before Derek can call out his name.

-

He doesn’t return to Beacon Hills that night. It’s not the first time he’s slept in a vehicle and it won’t be the last. He leans the driver’s seat back and tries to get comfortable even as he stares at his phone and contemplates for what has to be the hundredth time why he doesn’t call Scott and tell him that he’s found his best friend or let the Sheriff know that his son is alive and that he can put that bottle of whiskey away. 

He’s about to toss the phone into the passenger seat when it begins to vibrate in his hands. Chris Argent’s name appears on the screen and Derek hesitates before answering.

"What."

"There’s been a development," Chris tells him, and Derek actually lets his paranoia get to him as he scans the darkness outside.

"What kind of development?" he asks, searching for any sign of another soul near the beach.

"I may have inadvertently stepped on a landmine," Chris says, frustration evident in his voice. "I overestimated how accommodating some… old friends of mine are. They know now that a member of the new Beacon Hills pack is missing. I think they may take it as a chance to test Scott."

"Test him," Derek repeats, unease creeping up into his chest.

"It’s an outdated tactic. Wait for a weak moment and then apply pressure, see how the rest of the pack holds up. It’s a form of entrapment."

"Sounds like these friends of yours are real class acts," Derek sneers. He hears Chris sigh, but the man doesn’t disagree.

"I’ve already warned Scott. Just be careful. They’re likely to include you in this as well."

"… I’ll keep an eye out." Derek doesn’t thank him, but he hopes that Chris can hear it in his voice.

Any chance he had of sleeping soundly that night flies out of the window. Whenever he gets close to drifting off, something jars him back into wakefulness, be it a sound or a feeling. The waves do their best to lull him to sleep and but his own vigilance forces him to be alert once more against his will. This happens several times, well past midnight and into the very early morning.

Eventually the tiredness gets to him. Despite his instincts’ best efforts, he finally manages to fall into a light doze, existing in a fog. He doesn’t dream this time, but in the black nothingness he finds himself in, he’s almost certain he can distantly hear someone crying, despondent sobs turning to angry wails as waves crash against the shore.

-

Daylight doesn’t make him feel any better. Derek’s not stiff or sore, but he wakes up groggy and in a poor mood. It takes an embarrassing amount of time for him to get his wits about him and when he does he makes sure to walk up to the highway and take a look around. He doesn’t see, hear, or smell anything out of place but he takes his time walking along the higher ground.

The sound of heavy splashing draws his attention to the bluff that over looks ocean. There are no rails in the area, and an unobstructed path from the road leads straight to the edge of the cliff. Still perhaps not a danger, as the bluff is long and runs perpendicular to the road. Nevertheless, he follows many different tire tracks leading out to the edge. Most stop yards away and Derek assumes those who do manage to find their way out here considered it a great photo opportunity. There is one set of tracks however that seem to continue all the way out to the edge.

He hears another splash just as he looks over the edge, surprised to see Stiles swimming in a wide circle just below. Despite the steady, calming pace, there’s a tension in Stiles’ body as he moves that suggests what he’s doing is by no means a carefree action. The red and orange colors of his tail reflect the morning light making the pattern he cuts into the water seem like a trail of fire. It’s mesmerizing to watch. Eventually, though, Stiles stops circling and diving down far enough the Derek can no longer see him. He’s not sure how deep the water goes in this area but it’s certainly deep and murky enough to obscure anything a few feet from the surface.

He treks back down to the beach proper, already shedding most of his clothes and ignoring how loudly his stomach is growling. The water laps around his legs as he walks the length of the beach toward where he saw Stiles. Derek only gets a few yards away before he suddenly feels like he’s being watched. He turns to look up at the highway, but sees no one. Then, quick as a flash, something brushes passed him under the water. Derek tries to turn to keep it in his sights, but it’s already circled around him again.

"Stiles!" he growls irritably, trying to snatch the boy’s arm as he passes.

Whatever hesitation Stiles had toward him yesterday seems to be nonexistent now. He slips away from Derek but doesn’t go far, instead surfacing up to his shoulders. There’s a smartass smirk on his face when he suddenly lifts an arm out of the water, extending something in his strangely colored hand to Derek. After a beat, Derek takes it from him, surprised when he sees that it’s his old New York license, the one he’s sure Stiles keeps in his glove compartment.

I need a decent picture of you to send to the proper authorities should you ever take to creeping around the school again.

Stiles swims around excitedly, pointing to Derek’s face on the card. Turning to Derek, he exaggerates a frown and uses a taloned finger to push down his brow. It’d be something bordering ridiculous if not for the somewhat intimidating blackened eyes.

"Where did you get this?" Derek asks. Stiles’ mirth fades away quickly and he sinks back into the water. Concerned, Derek follows him out to the rocks. Sitting on his usual stone, he watches as Stiles swims around in some manic pattern that Derek can’t seem to make out.

There are so many questions Derek wants to ask, but Stiles hasn’t said a word since he found him. Derek isn’t even sure that he can in this state. He finds this silence more unnerving than the tail or the eyes, because Derek is pretty sure Stiles has never been silent in his life. But before he has a chance to contemplate any further, something slimy slaps him in the face. Sputtering, he jumps up and watches a fish flail back into the water. Shocked, Derek looks to Stiles who is gesturing angrily at him and the fish. Huffing loudly, Stiles dives back into the water. Seconds later another fish is tossed up to Derek and this time he manages to catch it. He punctures it with his claws just to get it to stop flapping around as he sets it on the rock. A second fish shoots out of the water followed by a third. He catches them both, frowning when Stiles head pops up. Annoyed, Derek holds the fish up.

"What am I supposed to do with these?" he asks. Stiles has the audacity to look at him as if he’s stupid. Swimming over to grab the fish on the rock, Stiles sinks his talons into it and then does the same with his teeth. Derek grimaces, but hell, he’s had his fair share of woodland creatures back home, so what right does he really have to judge? Glancing at the dead-eyed fish, however, Derek finds it hard to regain his appetite, especially with Stiles ripping away at his own.

Nevertheless, Derek hasn’t eaten anything since yesterday morning, as his stomach continues to make very clear. He starts wading his way back to the beach, intent on at least trying to cook the damn things when Stiles’ tail wraps around him, keeping him from going further. For a cold moment he thinks Stiles might be trying to drag him under again. But when he turns, Stiles’ face is pinched with anxiety.

"I’m just going up there. I’m not leaving," Derek tells him, holding up one of the fish. "Never was a fan of sushi." He’s not sure if Stiles gets what he’s saying, but he must because he eventually lets his tail fall away from Derek’s waist.

It takes him a while to scrounge up enough twigs and the like to make anything resembling camp fire fodder. He runs up to the Toyota and snatches up the zippo lighter he keeps in case of emergencies. He surprised to see Stiles dragging himself onto the beach, collecting Derek’s sticks and crawling further to drier sand. Concerned, Derek rushes back to him.

"Hey, hey, what are you doing?" Derek asks as he kneels next to him. Stiles rolls over onto his side to point to the tide which is beginning to creep up the sand. Stiles has already started arranging the sticks properly for a fire. "Been camping before?" Derek asks, retrieving the fish. Stiles pauses as if thinking his question over. He nods once, folding his arms and resting his chin against them.

Derek finds himself distracted by the stretch of Stiles’ body on the beach. His tail, which is still catching a bit of the waves, is longer than his legs were once, the narrowing shape of it accenting Stiles’ torso and the color along his spine bringing out the moles dotting his back. He’s swimmer lean, gorgeously laid out on the sand and Derek angrily tries to tell himself that now is not the time.

Having grown impatient, Stiles grabs the lighter from Derek’s hand and deftly flips it open, lighting it without problem and starting a fire in the sticks and dry leaves. There are obviously things Stiles does and doesn’t remember, Derek thinks as he prepares the fish, but he seems to understand that how he is now is not how he should be and it’s a clear point of aggravation for him if his longing glances at Derek’s legs are anything to go by. As they wait for the fish to cook, Derek brings his old license out of the pocket of his trunks.

"Stiles, I need to know where you got this," Derek says. Stiles looks up from Derek’s toes to blink his inky eyes at the card. With more than a little hassle, Stiles manages to back himself fully into the water again, swimming to the area beneath the cliff again. Derek stands and moves to watch for him, but he doesn’t have to wait long. An arm pierces the surface, Stiles’ taloned fingers clutching a set of familiar keys.

-

Derek has to go back to Beacon Hills that night. He needs to meet up with Scott, check on the Sheriff, and talk with Deaton. The distance from the beach does nothing to soften the memory of Stiles’ face when he left. Not betrayal, no, but the damning loneliness that Derek knows all too well. He has every intention of telling Scott where his friend is in the morning, to take him to the beach and watch a reunion fit for some summer romance blockbuster.

As Derek stands in the shower to wash the sea salt off of his skin and out of his hair, he goes over a list of all the things he needs to do tomorrow. The farther down the list he goes in his mind, the more he feels some dark anxiety creep up in his chest. Perhaps, he thinks, he should investigate all this first. He’s plenty capable of doing research without Deaton. Scott and the Sheriff are in the search for the long haul, they’ll be fine for now.

Yes, he thinks as he lies in bed and breathes in the ocean air that shouldn’t be there. Why burden them with this mystery when he is the one Stiles reached out to by some unknown means? This is on him to figure out. For now he’ll stay quiet.

For now he’ll keep Stiles to himself.

-

The Jeep is a sad sight under the water. It was a sad sight to begin with, but seeing it like this does something to Derek’s chest that has nothing to do with holding his breath. The driver side window has been broken and Stiles swims easily through it, moving around in the darkness of it before coming out to show Derek what he’s found. Squinting at it, Derek sees that it’s Stiles’ cell phone, nothing more now than a brick. Stiles goes back to the Jeep but Derek has to surface for air.

The sound of a gun cocking is unexpected but unmistakable.

"Have a good swim?"

Derek spins around and freezes at the sight of a shotgun barrel aimed at his head. There’s a man on the lower outcropping of the bluff where Derek has stashed his clothes, his posture and the cruel tone of his voice leave no room for doubt as to who he is.

"Let me guess," Derek says, pushing back his wet hair. "You’re a friend of Argent’s."

"Friend is such a strong word," the man says bemusedly. Derek chances a glace around the beach, trying to pinpoint whether or not the hunter is alone. "I need to have a little chat with Scott McCall."

"Then you’re about 70 miles too far south," Derek tells him with false cooperation, mind working itself in a frenzy. How quickly can he get himself on solid ground? Quick enough to disarm the hunter? Those are most likely wolfsbane bullets. What about Stiles? The moment he surfaces, he’ll be a target too. Can Derek subdue this guy before that happens?

"Oh, I’ll be making my way back to Beacon Hills soon enough. I didn’t follow you here just for the ocean view," the man say, gesturing out to the horizon with his gun. A panic seizes Derek as he wonders if the guy has seen Stiles already. "You’re going to be my assurance that our talk will be a friendly one. He can’t really afford to lose any more pack members."

"Scott McCall isn’t my alpha," Derek says absently, eyes very quickly scanning the water for Stiles. He can’t see him.

"Whatever you say, big guy," the man says. "Swim’s over. Get out of the water. Slowly."

The man backs up to allow room for Derek to pull himself onto the outcropping. Derek cautiously rises up to his full height, eyes flashing. The hunter’s easy attitude wavers, but his gun does not; if anything, his aim becomes more steady. Despite this, Derek makes a run at him with his claws extended, hoping to catch the hunter off guard. 

The lightning flash of pain that explodes in his chest proves otherwise.

He pitches forward, hands clutching torn flesh. He’s vaguely aware of the hunter moving behind him out of reach of his claws, but Derek is trying his hardest just to keep breathing. He can feel the wolfsbane leeching into his veins, every beat of his heart is like a dagger working its way from the inside out.

"Damnit!" he hears the hunter curse. Somehow he manages to turn onto his back, teeth gritted together so strongly that they might break. The shotgun is reloaded and cocked again, raised to fire a finishing round.

With his back now to the sea, he never notices Stiles. Not until he explodes upward from under the water, arms wrapping tightly around the man, jamming his talons into the his throat. He has just enough time to shout as Stiles drags him over the outcropping. There’s frantic splashing to accompany the hunter’s struggle, muffled gasping as he manages to break the water’s surface once or twice.

And then nothing.

An eerie silence falls, broken only by the waves and Derek’s wet, painful breathing. He feels his pulse pump the poison closer and closer to his heart and his vision begins to blur and fade. Just as he’s sure he’s about to pass out, something is forced up out of the water. The hunter’s gun lands next to him with a clatter and Derek musters up what strength he can to grab it. Getting to his jeans is more difficult, but eventually he’s able to shake his lighter out of it. His hands are shaking as he opens the gun and tries to retrieve one of the shells.

He blacks out with his cure in his hand.

Death isn’t what Derek expected it to be. There’s no white light, there’s no blackness, just the intense display of bright colors dancing in front of his eyes with a cool weight against his chest and along his front. Stiffly raising a hand to touch whatever it is, his fingers find themselves buried in someone’s hair for a split second. The head that was just ear down on his chest immediately shoots up and a punch is delivered to his shoulder.

Growling low, Derek opens his eyes and regrets it a second later. Before he can shield himself from the sun, Stiles’ head does it for him, looking down at him with those black eyes. But as soon as Derek takes his first deep breath in what feels like hours, Stiles pulls away, shuffling himself backwards awkwardly until his tail flops heavily back into the water. Derek places a hand on the healed skin of his chest, turning his head to see the emptied shotgun shell and his opened lighter. Lifting himself onto his elbows, frowning when he takes in Stiles’ unimpressed, frustrated expression. Derek can just hear the words with irritatingly clarity in his imagination.

You had one job.

-

Derek returns to Beacon Hills with a warning on his tongue and a fierce protectiveness in his heart. Scott needs to know what happened, that the rest of his pack is in danger, that he’s in danger.

His visit doesn’t go quite as he’d hoped. For one, he finds Scott at the hospital.

"Where have you been." There’s hurt and accusation in Scott’s voice. Derek says nothing as he looks into the room where Melissa is checking the Sheriff’s vitals. Exhaustion and sadness overpower the man’s scent, combining into a weary sickness. The man is worrying himself to death. "If you’re not going to bother helping, you shouldn’t be here," Scott says.

"I’ve been helping," Derek says defensively. Scott ignores him.

"I get that you’ve never liked Stiles, but he’s important,” Scott stresses to him, his voice breaking slightly. “We need him. His dad needs him. I need my best friend back!”

"I know that! He’s-" alive and different and desperate to come home.

But the sudden taste of sea water on his tongue keeps him silent. No, he thinks. Not now. He shakes his head and meets Scott’s expectant stare.

"He’s going to be found. We’ll find him," Derek finishes. The anger on Scott’s face doesn’t fade, not even when the Sheriff weakly calls for him from inside the room.

"By the way, nice tan," Scott says through his teeth, roughly bumping shoulders with Derek as he passes to walk to the Sheriff’s side.

-

The Hale family once had an extensive library, one that used to be his father’s pride and joy. It, as with much of Derek’s life, went up in flames so many years ago. Very little of it still remains, mostly local histories and detailed notations of the surrounding flora and fauna. Because of this, Derek is a little more than unhappy with how often they’ve had to rely on the Argents’ bestiary.

There is a section for sirens and mermaids, but most entries on their characteristics are categorized as “Unconfirmed” or “Debated” with very few solid facts. There’s one particularly amusing entry questioning whether or not biting the detached scales of a siren’s tail can allow for underwater breathing. In different handwriting, someone had scribbled You’re a goddamn idiot in the margins years before the pages had been scanned into PDF form.

The facts are more disturbing.

Carnivorous.
Capable of mesmerizing and drowning its victims.
Cannot be reasoned with.
Recommendation: Kill on sight. Harvest remains.

-

He finds Stiles face down on the beach. Without even sparing to look for more lurking hunters, Derek abandons the Toyota and races down to him. Stiles’ skin is sun-warmed to the point of being worryingly hot to the touch. His tail is dried out, its once brilliant color faded like old paper.

"Stiles!" Derek holds a hand on Stiles back, only to pull it away with the scales of his spine flake off. Grabbing him by his peeling shoulders, Derek turns him over, wiping the sand from his face. Stiles’ lips look painfully chapped, and Derek has to wonder how long Stiles has been lying on this beach so far from the waves. Derek shakes him a couple of times yet gets no response. When Derek picks him up, one hand behind his back and the other under his tail, something falls from Stiles’ fingers. Derek pays it no mind as Stiles startles awake, glancing around fervently.

He looks back to Derek with doe brown eyes. He opens his mouth to say something and Derek waits for it, heart in his throat; but instead of speaking, Stiles grits his teeth, flailing his tail once. A shower of scales falls from it.

Panicked, Derek makes a dead run for the ocean. He only wades to waist-deep water before practically throwing Stiles into waves. The tide drags his body further out, but Derek stays rooted in his spot watching intently. He lets out a sigh of relief when he sees Stiles right himself under the water and swim in briefly in a concentric circle.

His relief wanes when Stiles surfaces near him, eyes black once more and a deep anger in the set of his jaw. Derek moves to get closer, to calm him in some way, but Stiles turns from him, his once again vibrant tail violently slapping water into Derek’s face as he swims farther out than Derek knows he can follow. He stands there for a few minutes more before turning and making his way back to the beach.

What Stiles dropped was a crumpled photograph distorted from too many days in salt water. Despite the damage, four figures are clear to make out. Stiles, his father, Scott, and Melissa are all grouped together at what looks to be the lacrosse field during the night of a game. All of them are smiling to some degree, all of them seem happy.

-

He sits out on his rock for what has to be hours, waiting patiently for Stiles to come back; because he will, he has to. At the very least, Derek has to believe it’s true. He needs to take Stiles home. He needed to do that from day one and doesn’t understand his reluctance all those times before. When he thinks over his actions, very few make any rational sense. He only has a vague understanding of what has happened to Stiles, but even then his mind is working on half theories that he mysteriously hasn’t bothered to think through.

The whole thing makes him nervous with a creeping anxiety he can’t place or give name to.

He does see Stiles again after a time, just as the sun is about to go down. So lost in his own thoughts, Derek wonders if that half face in the water has been there for much longer than since he’s been aware of it. Slowly, Stiles swims toward him. His irritation with Derek is still evident, but something about his hunched posture suggests a begrudged sort of apology. And the fish Stiles tosses into his lap. The posture and the fish. Definitely apologies. 

"Thanks," Derek says with a grimace, holding the flailing thing by its tail.

With a splash on impatience, Stiles grabs the fish and throws it over his shoulder, placing his hands on Derek’s knees and using them to lift himself up. For a moment, Stiles is stretched up close enough that Derek thinks he’s about to kiss him. Instead, Stiles points over his shoulder to the beach. Turning his head, all Derek see is his Toyota up near the highway.

"Are you ready?" he asks, not bothering to specify. Stiles nods but lets himself rest against Derek’s lap, fear clear in his black eyes. Derek ignores the warmth he feels at the tips of his ears and runs a hand down Stiles’ colored spine.

-

Stiles’ tail is wrapped up in the towels Derek brought with him, both soaked in the sea water before he places Stiles in the back of his vehicle. It’s a little over an hour back to Beacon Hills. Less if he guns it, but the risk of being pulled over for speeding is too great.

He drives so cautiously, it takes them an hour and a half. It’s already night when they pull into town, but Derek knows that one phone call will have everyone up, alert, and at Stiles’ side within minutes.

Instead, Derek drives them to the Preserve. There’s a stream not far from the his old house. For now, Stiles can stay the night there, have time to gather himself and fend off the panic attack Derek can hear building beneath his ribs. Stiles seems to immediately relax when Derek places him in the shallow water surrounded by quiet woods. Still, Derek can see the frustration in the down turn of his mouth.

"It’s fine," Derek tells him. "We’ll call them tomorrow. One at a time."

Stiles splashes him, because the kid is a dick. But he also smiles, because he is grateful.

-

Derek sleeps fitfully on the pathetic excuse for a mattress in the burnt out shell of his childhood room. Just when he’s about to fall asleep, ghosts appear in memories. The time Laura flipped his bed to get him up on a weekend morning, or when Cora refused to sleep in her own room because a hunter was under her bed or in her closet. Phantom voices of his parents telling him to hurry and get ready for school, Uncle Peter yelling at the TV during March Madness.

The scent of a mouthy, sarcastic teenager who’d been missing for weeks.

Derek shoots up into a sitting position, focusing his ears downstairs. When he definitely hears movement, he’s out of his room and over the stair banister in the blink of an eye. From his position stretched out on the only remaining couch, Stiles, brown-eyed once again, raises an eyebrow.

"Are your stairs at risk of collapsing or are you just that much of a drama queen?" His voice is hoarse from disuse. Derek finally takes in the rest of him, noticing the legs that now replace the tail.

"Are those my clothes?" Derek asks, already knowing the answer.

"You had a bag near the door. I figured you wouldn’t mind sharing if it meant not seeing me naked."

Derek wants to say that he’s already practically seen him naked. He doesn’t.

"Did you let yourself dry out at the stream?" Derek asks, playing toward a theory. Stiles looks at him for a moment before nodding.

"It actually really kind of hurt," he says, wiggling his toes. "I can’t really walk right yet."

"Stiles," Derek says, walking closer. "What happened? How did this-" he gestures to Stiles’ legs, "-happen?" Stiles stares at his bare feet for a while, curling and uncurling his toes a few time.

"I thought I heard a woman singing," Stiles finally says. "It sounded like my mom."

"And you just followed it?" Derek asks. Stiles gives him a pissy look.

"So did you," he says haughtily. "I didn’t even have to sing."

Derek blinks and remembers the scent of the ocean.

"You called for me."

"I called for anyone, I guess," Stiles says. "You’re the only one who came." Before Derek has a chance to take some kind of pride in this, Stiles adds, "Makes sense. I mean, you’re the most easily manipulated man on the face of the planet, dude."

"Why did you keep me from saying anything?" Derek asks, choosing to ignore the slight. "We could have helped you days ago."

"… I was scared," Stiles says, as if it’s the last thing he wants to admit. "I couldn’t remember who-… I couldn’t remember. One minute I’m following a voice, the next I’m fucking drowning because I drove over a cliff. The next next thing I knew was nothing. Just that something wasn’t right.”

"So what now? You think you’re back to normal?"

"I think," Stiles says slowly, glancing out of a nearby window, "that I’m going to be screwed the next time it rains."

A tense quiet falls around them then and Derek tiredly rubs a hand down his face as he sighs.

"Get some sleep. Do you think you’ll be ready to see everyone tomorrow?" he asks. "Your dad really needs to see you." Determination steels itself onto Stiles’ face.

"Yeah," he says mostly to himself. "Yeah, I can do it."

Derek nods, about to make his way up his still very sturdy staircase thank you very much, when a thought crosses his mind.

"Did you really have to do the other thing?" he asks. Stiles blinks at him, confused. "The infatuation thing. I would have stayed and helped, you didn’t have to do that."

"What the hell are you talking about?"

They stare awkwardly at each other for a moment before Derek coughs and turns away.

"A problem for another day," he says, pausing to press a finger into the sole of Stiles’ foot which twitches violently.

"Ah! Hey!"

The blush that floods his face is as brilliant as his tail once was.

Chapter Text

"It's interesting, don't you think?" Lydia had mused. "Stiles always had this fear of drowning and now, not only has it happened more than once, but it's made him like this."

"It's not interesting," Scott told her. "It's cruel."

-

It's odd, actually, how Stiles seems to have no desire to learn more about what's happened to him. The frenetic curiosity he had for Scott's turning is almost entirely absent. He doesn't ask for references, he refuses to see Deaton, he won't even stay in the room when the issue is being discussed. The Sheriff is just happy to have his son back, in any form he can have him, but it worries Scott, and that worry leeches into Derek.

He should be angry when the feeling of sand beneath his toes forcibly keeps him from asking Stiles about it. That nervous, limb-locking anxiety is completely Stiles' doing, he knows, and it's mildly infuriating that the kid would intentionally influence him like this. But when he thinks about it, it isn't very different from an Alpha communicating to its pack through instinct.

He doesn't want to talk about it, and he's letting Derek know the only way that's been proven effective. Derek doesn’t think the scent is intentional, because Stiles isn’t talking to him right now, but the kid is reaching out for something, and Derek figures he might as well be it.

-

That doesn't mean he always has to like it. This constant state of avoidance that Stiles has put himself in is beginning to impact his health. Dehydration headaches are common place now, and there's only so much deodorant he can drench himself in, only so many things he can do with his greasy hair before it becomes obvious he's been putting off bathing. It's only a matter of coincidence that Derek is at the police station, arguing over a parking ticket with Parrish, when the Sheriff finally puts his foot down.

Their conversation lulled, both Derek and Parrish watch the Sheriff's office cautiously, the sounds of muffled, raised voices coming through the walls. Parrish strains to makes out the words, but Derek hears them clear as day.

"-and I don't understand why you're doing this to yourself!"

"It's not a big deal, Dad!"

"The hell it isn't! I won't see you waste away just because you're scared, Stiles, that's no way to live."

Derek is almost blind-sided by phantom waves, an invisible tide that threatens to pull him under a blanket of fear and shame.

The next time he sees Stiles, he's cleaned and well hydrated, face haunted and defeated.

-

Derek asked Scott once if he could smell the sea from time to time. Scott had looked at him like he was crazy.

Maybe Stiles had been right before. Maybe Derek is just that easily manipulated, receptive to suggestion and the wayward emotions of a distraught teenager. Whatever the reason, Derek seems tuned in to Stiles' siren call, if it could even be called that.

He feels it often before the oncoming of a storm, when dark clouds hang low in the sky and the temperature drops. Derek knows from Scott that they either take steps to make sure Stiles is covered from head to toe before going to school or Stiles' dad calls him in sick. It's a system that Stiles hates and find tedious, but one that works.

So Derek is understandably confused when the mild taste of salt water at the back of his throat explodes onto his tongue and into his nose. He drops the book from his lap, breath coming in slow, labored pants. Peter, who had been lingering around the windows, looks at him curiously.

Derek ignores him and races out of the building.

-

The rain soaks through his clothes, the material clinging to his body like seaweed. It's annoying and stifling, but that call is stronger, more demanding of his attention, pulling him through trees and down deserted streets. He doesn't stop until he's skidding in the mud outside of the Stilinski home.

The Sheriff's cruiser is absent, but the Jeep is halfway in the garage, still running with the driver side door wide open to the onslaught of rain. Derek jogs up and reaches for the keys, turning the engine off and glancing around for any sign of where Stiles could be. There are scratches in the seat running long and thin down the side, and a piece of denim is stuck in the side panel. With his breath caught in his throat, Derek closed the door and looks around.

Just off of the driveway he finds water gathering in a long trench-like groove in the ground that trails further back around the house. The rain and Stiles' panicked sea salt calling makes it difficult for him to catch a scent so he makes his way to the back cautiously. His unease grows when he finds a discarded pair of shredded jeans in one of the puddles, so he rounds the corner ready for anything. And there, under the porch light of the kitchen door, Derek sees him.

Covered in wet earth and clawing desperately at the door, Stiles is trying to drag himself up to the handle. Just as his taloned fingers brush it, his heavy tail slips off of the steps, dragging him back down with a splash into the mud. Derek winces, his heart sinking somewhat. The feeling gets worse when Stiles doesn't immediately push himself up to try again. Instead his tail moves to wrap around him, providing some refuge from the rain, but Derek is surprised when Stiles angrily pushes it away. Derek steps forward then, clumsily pulling off his jacket and holding it over Stiles' upper body.

Stiles starts when he realizes he's not alone, but Derek doesn't need the bitter taste on his tongue to tell him the shame Stiles is feeling. It's written all over his face.

-

It was one thing, apparently, to let Derek carry him inside. It seems to be another entirely to help him clean up. Derek didn't get much farther than placing Stiles in the bathroom and grabbing the hem of his mud drenched t-shirt before Stiles flailed his tail against the tile and pushed Derek out of the bathroom, slamming the door closed. It opens again briefly, just wide enough for a towel to be shoved through before closing again. Bewildered, Derek stares at the door for a moment, sighing and sitting down next to it, listening to the sound of the hair dryer as he begins to peel off his wet shirt and pat dry his hair down.

He's contemplating trying to wrestle out of his jeans, the material having grown heavy and uncomfortable, when he hears it. The sound is soft at first, a sharp intake of breath that becomes a pained exhale along with the wet tearing of skin. Derek's never actually seen Stiles change, but the sounds alone are unsettling.

Kind of hurts, Stiles had said. No fucking kidding, Derek thinks.

He can't help but look at his own hand and feel the easy shift of his claws. The tendons in his hand strengthen and grow, rippling under his skin. It feels like nothing more than a muscle spasm, a pulsing so brief he rarely thinks about it. Sometimes his fangs itch around the gums, or the skin pulls too tightly too quickly around his face. His full shift is nothing more than a rearranging of bones that slide against each other as if it were nothing, flesh and muscle moving in a smooth transition and retaking shape naturally.

It's nothing like what he's hearing beyond that door.

-

"Did you really have to kick me out?" Derek asks as he hands Stiles a pair of sweats and turns around.

"Did you really have to stay?" Stiles snipes back. Derek presses his mouth in a thin line but tries to be understanding. Stiles is angry and embarrassed and feeling not just a little defensive.

"I've helped you before. Why won't you let me help you now?" he asks. Stiles is suspiciously quiet enough behind him that Derek chances looking over his shoulder. The tired, bitter glare that Stiles gives him almost makes him flinch.

"You like me like that," Stiles accuses. Derek swallows, not sure what to say.

"You're a brat either way. What difference does a tail make?" he eventually tells him. They both see it for the flimsy diversion it is.

-

Derek leaves the house with the bottom of his stomach falling out. Because Stiles is right, in a way. There's something addicting about being needed, and Stiles does in that state, need him. It's been too long since Derek has felt like this. Useful, capable, special; he can feel Stiles' call, even when Stiles doesn't want him too. Such a reckless, taunting, strong person like this kid needing someone- needing Derek's help is as intoxicating as it is alarming and something in him revels in it, even as Stiles suffers.

It's not a side of himself that he's proud of.

-

"Scott, you have strength, heightened senses, and your face does that cool thing when you wolf out. Know what I get? About seventy pounds of dead weight on land. How, exactly, is that any good to anyone?"

"I'm not saying it has to be useful, Stiles," Scott says patiently. "I'm just saying that we haven't found anything on how to change you back, just like we couldn't change me. And well, I mean, I got used to it eventually so-"

"No."

"Stiles, man, come on. You have to-"

"I don't have to do anything."

I don't want to do anything is all Derek hears from his place an aisle over. Stiles' reluctance to accept his condition is as clear as the ocean air Derek picks up instead of too-ripe produce. Scott tries again to get Stiles to talk to him, but when Stiles once again brushes it off, Scott speaks up a little louder.

"Derek, could you help me out here?"

Derek freezes, grapefruit in hand as he turns to the cereal aisle and sees Scott poke his head out to look for him. Before Derek can make a hasty retreat, Stiles' head joins Scott's. But where Scott's face is pleading, Stiles' is furious.

"Did you follow us here?" he asks. The venom in words surprises Scott, but Derek resists the urge to duck his head. Scott looks genuinely lost when Stiles throws up his hands and starts walking toward the exit. Scott looks between them before gesturing to get Derek to follow him, but Derek shakes his head sharply. Scott gestures more frantically with his arms and Derek gives up, sighing as he places the grapefruit back and setting down his hand basket.

Both of them barely make it out of the store before Stiles halts suddenly once he enters the alleyway and turns back around on them.

"What's so bad about wanting to be human, huh?" he asks without provocation. "Humans don't have to worry about mauling people once a month or getting fang lisps." Derek self-consciously rubs his tongue along his incisors and is pretty sure he sees Scott do the same out of the corner of his eye. "Humans have landed on the moon. Have werewolves or fish people landed on the moon? I don't think so!"

"But you're not human anymore," Scott says calmly. "And if you're not going to accept that then we need to actually do something about it." There's sadness and frustration in his voice, and Derek knows he'd give anything to help Stiles the way Stiles wants to be helped, to be cured or to have everyone ignore it. But a cure isn't in sight and there are people in his life who refuse to let him return to his pattern of avoidance.

"It can be managed," Derek says, and he believes it. Believes it because he's thought about it for hours at a time. That maybe Stiles' shift is so painful because he fights it or because he goes for long periods without it happening. That maybe he can learn to communicate with others beyond his current means. That maybe, just maybe, he can learn to not be afraid of the water.

But when Scott stiffens beside him, when Stiles begins to flush with anger, Derek knows he's said something wrong.

"Managed," Stiles repeats coldly, and then echoes his father. "Like that's any way to live."

-

A few weeks pass, as do more arguments, because Stiles is nothing if not infinitely stubborn and Derek is no better, even on his best days.

“Derek, come on in. Thanks for stopping by,” the Sheriff says, stepping aside to let Derek into the front hall, who then gives him a brief tight-lipped smile. 

“Your message didn’t sound urgent, but I was in the neighborhood,” Derek tells him.

“Stiles has been getting a little restless since the weatherman predicted rain for the next couple of days,” the Sheriff sighs. “Would you mind taking him and Scott to the beach this weekend? I have to cover for a deputy who’s on maternity leave." 

"Actually,” Derek starts, shifting on his feet uneasily. “Stiles isn’t really… happy with me, I guess.” The Sheriff pauses in bringing his coffee cup up to his lips.

“What did you do?” he asks mildly.

“I- I may have made the assumption that he, uh. Ate the hunter who attacked me,” Derek says with a wince. The Sheriff gives him a long look, one that’s decidedly unimpressed.

“Stiles will only eat poultry and fish because he thinks cows have likable faces.”

“I know, I just- I thought maybe there was a chance the change might have been more than physical, going off some records I found,” Derek says, averting his eyes. 

“Son, if you think sprouting a tail is going to keep Stiles from being Stiles, I’ve got news for you,” the Sheriff says, walking toward the kitchen before turning back and pointing a finger to the stairs. “Go apologize.” The order is just as strong as one of Stiles’ calls and it has Derek making an immediate trek to the second floor. 

He pauses on the landing, gathering his courage before he realizes how ridiculous it is to be afraid of Stiles Stilinski of all people. Squaring his shoulders, he pushes the bedroom door open. It only takes a second for him to realize that Stiles isn’t in it; the laptop is closed and the room carries the chill indicative of a space that hasn’t been warmed by someone’s body heat. Confused, because he clearly still smells Stiles in the house, Derek focuses he hearing and picks up the gentle splashing of water coming from the bathroom. Rubbing his suddenly sweaty palms against his jeans, he knocks on the door.

"Stiles?" 

Nothing from the other side. Derek tries again.

"Your dad wants me to take you to the ocean tomorrow. Scott too. Stiles?” Derek persists, brow creasing. There’s another splash from inside the bathroom and water suddenly spills out from bottom of the door. Impulsively, Derek grabs the knob and swings the unlocked door open. 

Hanging over the edge of the tub is that familiar bright red and orange tail, swinging lazily from side to side. Derek looks over into the tub and finds Stiles submerged, eyes closed and chest rising and falling slowly. He’s asleep. Derek feels an irritated tick in his jaw, but ignores it in favor of poking the part of Stiles’ tail that’s out of the water. Immediately Stiles’ eyes open, wide and completely black. He must recognize Derek’s shape above the water because he frowns crosses his arms, pulling his tail more fully into the tub. Derek side-steps to keep as much water as possible from getting on his shoes. 

“Hey, come up for a second. I need to talk to you,” he says, kicking the porcelain gently.

He’s gets a wet, scaly tail in his face for his troubles. It lands on his shoulder and along his front, so he grabs it and pulls, walking backward. Stiles flails as he’s pulled from the tub, water flying everywhere. He hits the tiles with a wet smack, but Derek knows better than to think he might actually be hurt. Stiles proves it by leaning up on his elbows and giving Derek the finger. Derek rolls his eyes and immediately regrets it when Stiles flails his tails around, knocking him behind the knees and pulling his feet from under him. He lands on his back loudly, water instantly soaking into his jeans and shirt. He grits his teeth and growls at the ceiling. 

“You don’t make saying sorry easy, you know that?" 

Stiles’ tail flops into his face again. Derek can’t wait for him to dry out, if only so Stiles can go back to yelling at him. 

The Sheriff peers concernedly into the bathroom, taking in the mess of water, werewolf, and fish boy sprawled out on the tile. 

"Maybe I should have just asked Melissa.”