A/N: Hey guys! I know I'm supposed to be working on "Beast" - and I swear I am, the next chapter is almost finished and should be up tomorrow - but babe (my beta) and I got an idea and we just had to go with it. And actually publish it for once, because this isn't the first time we've gone into Sterek mode. I hope you guys like it! :)

Oh, and for those of you who aren't familiar with it, the song is "Every Breath You Take" by The Police, which is of course where the title comes from.


ONE

Derek rolls his eyes as he hangs up the phone with the Sheriff and grabs his keys before heading over to Stiles' house to pick him up. When he gets there, Derek parks out on the street and sighs before getting out slowly and walking up to the Stilinskis' door and ringing the doorbell.

He hears Stiles jumps down the stairs, stumbling as he heads to the door. "Shit." Derek rolls his eyes at the yelped curse before Stiles steps out onto the porch and looks up at the sky. "Doesn't seem to be any apocalypse happening or anything... no flying pigs... hell probably hasn't frozen over past the seventh circle..."

Shoving past Stiles, Derek walks into the house. "Grab whatever you need to keep yourself occupied for a few hours."

"By all means, c'mon in," Stiles snarks, closing the door and going back upstairs. "Why do I need things to occupy myself for a few hours?"

Derek huffs and heads up behind Stiles. "We're going on a stakeout."

Stiles hums in acknowledgement as he grabs a book, his Gameboy, DS, 3DS, and a few games for each. "What are we on the lookout for now?"

Derek watches Stiles pick up all three handheld devices and stuff them all in a rucksack. "You really don't need all of those, and I'll tell you on the way so can you please hurry up."

"Uhh, have you met me?" Stiles snorts. "And since when do you willingly take me with you?"

He starts to head downstairs when he hears Stiles' last question. "Who said I was doing this willingly?"

"Real nice, Derek. I feel the love." There's the sound of rustling fabric, probably Stiles throwing the strap of the rucksack over his shoulders, before footsteps follow behind.

"Hurry up," Derek growls, out on the porch.

"Chill, you ass, I'm coming." Stiles locks the door behind him and heads to the Camaro.

Derek gets in and the second Stiles closes the door floors it and heads back toward the Preserve.

In the corner of his eye he sees Stiles grab the dashboard as he slides forward a little. "What the hell, dude? Someone dying? Why're you speeding toward the Preserve like a bat outta hell?"

Grunting, Derek slows down a bit. "Someone could be dying. We're looking for a girl, relatively tall, long wavy brown hair and olive-tinted skin. We'll be on our side of the river, since she's most likely been coming in from the other side since I haven't picked up anything on our side. She'll most likely have a younger guy with her. We'll be in view of a popular jogging route, but the car will be out of sight. Just keep your eyes open and if you see a girl trailing a guy off towards the river and she starts to sing, cover your ears."

Stiles looks at Derek, mouth gaping. "We're looking for a siren? How the hell did she end up here?"

As they get closer to the Preserve Derek slows down with a shrug and pulls off close to the jogging trail that crosses boundary lines. "No idea."

"Fucking nemeton, drawing all kinds of evil creatures here," Stiles groans.

There's a nearby hill that can't really be seen from the path; Derek drives up it and parks the car. He rolls down the windows, gets out of the car, and walks around to Stiles' side. "We'll take turns. I left the keys in, turn on the radio if you want but keep it low. I'm going to sit closer to the edge so I can keep an eye on everyone that passes by and see if she's down there." He walks over to the edge that's maybe just 15 feet away and sits and just watches. He can still hear Stiles and a good amount of the area around them so that he can make sure Stiles is safe like the Sheriff asked.

From the button mashing coming from the car, Derek can tell Stiles is playing some sort of videogame but not what – not even the muttering and swearing can give him a clue. The quiet – filled only by Stiles and a few runners - apparently either gets to him or he gets bored after a bit so he turns on the radio. Derek sighs. Eventually "Every Breath You Take" comes on, making Derek grimace. When it gets to the chorus Stiles bursts out laughing. "Oh my god, Derek! This is your theme song!"

"Shut up. Turn that crap off," Derek growls.

"Nope!" Stiles sings along with it loudly.

"You're going to blow our cover!" He looks down and sees a girl running into the woods that he hadn't noticed before. She's by herself but Derek can hear her laughing and humming.

Growling again, he stalks back towards the car. "Thank you for being both obnoxious and ruining the stakeout." Derek gets back in the car, shuts off the radio and turns the engine on so he can roll up the windows before turning back to the path that led them in to the Preserve.

Stiles rolls his eyes. "It wasn't that loud, jackass. And look, she had no victim."

Derek speeds out of the Preserve and back on the road. "It doesn't matter! You sang, she heard, she left. She could've had someone and you could've risked their life all because of a fucking song."

"Whatever," Stiles grumbles. "I was just trying to make something boring as hell a little fun but if you really think I'm a hindrance then don't even bother bringing me next time."

Keeping his foot heavy on the gas pedal as they head through town to Stiles' house, Derek growls. "Trust me, I won't. Next time your father can babysit you or send Parrish to do it."

Stiles snorts. "I doubt she's gonna come after me when she sees what sort of friends I have, but if she does I can protect myself."

A huff of laughter comes out of Derek's mouth as he pulls up in front of the house. "That's exactly why she would come after you, but I'd love to see what you of all people would do to protect yourself when you're being led to a watery death by a pretty girl."

"I'm not as helpless as you seem to think, Derek." Stiles slams out of the car and into the house without another word.

TWO

It's been about two days since the fight and the siren has yet to show her face. Derek hasn't heard from Stiles. The same can't be said about Parrish and the Sheriff, who are constantly calling and texting him. They start as inquiries about the stakeout but turn into the Sheriff asking him why Stiles seems to be in a bad mood. Derek tries to shake it off and avoid it, but when he finds himself in the Stilinskis' neighborhood he can't help but head over to their house. He climbs up onto the part of the roof that usually allows him to slip into Stiles' window, but he notices it's not completely open even though Stiles is home. Derek freezes and just sits there for a while trying to decide what he's going to say. It's hard to think when all he can hear is this constant knock of what he assumes is a lacrosse ball beating against the wall every few seconds, and he stops trying altogether when he hears Stiles muttering something about Derek avoiding him and not being a damsel in distress. Derek sighs, still not sure if he should go in or not so he sits there for a bit longer.

He's just about to leave, not willing to risk another fight while Stiles is still aggravated about their previous one, when he hears music start to play softly from the room below him. Derek just gets angry when he realizes it's that same fucking song from the stakeout. He's about to jump off the roof when Stiles snorts, "Should start singing or humming this whenever Derek's being a creeper."

Growling louder than he expected, Derek sighs as he slinks through the window, knowing he can't leave now, and just stands awkwardly by Stiles' bed. "Please don't."

He watches as Stiles spins his chair around so fast it tips over and lands on top of him as he falls to the floor. "Ow…" Stiles groans as he rubs at the hip and elbow he landed on before Derek finds himself on the opposing end of an accusatory finger. "What have I told you about sneaking up behind me period, let alone in my room?"

Derek just rolls his eyes and walks over to Stiles, pulling the chair off of him and reaching out a hand to help him up, all while ignoring the unnecessary anger. His hand gets slapped away as Stiles makes it a point to get up by himself.

"If you're not going to answer that question, how about you answer this one: What do you want? I haven't seen you since I 'botched' your stakeout." The quotations are clear in his voice as he sits back down in his chair and turns to his computer, the song still playing. "There been another killing? Need me to do some research?"

There Stiles goes again, never making this easy on Derek and making him sigh as he sits on Stiles' bed. "I came to apologize…" It comes out more whispered than an apology should, but he knows Stiles hears him.

"Um…" Stiles pauses, fingers switching over the keyboard. Derek hears the thick swallow before he looks up to see Stiles shaking his head. Taking a deep breath, he notices the slight spike of happiness in the teen's scent before standing and walking over to stand behind Stiles.

"So we didn't catch the siren in the Preserve by the river the other night," the boy finally continues after he seems to have pulled himself together. "But I was thinking we could try catching her somewhere else. Maybe by the college where the woods are right behind one of the dorms. Or is college age too old?"

Derek notices that Stiles won't meet his eyes, but he sums it up to Stiles being too busy reading whatever he has pulled up in front of him. He leans over the boy's shoulder to take a look for himself, smelling the happiness again as he leans so close their cheeks almost brush.

"The bestiary didn't really specify the age range for a siren's victims, just that they were young men, which is a pretty broad qualifier…" This comes out rushed – though Stiles doesn't trip over his words - but Derek tries not to read too much into it.

"We could try that, but the only crucial thing is wherever she's going to strike will be by a body of water and the river isn't exactly close to campus."

The boy hums in thought and Derek leans a little closer without noticing. "Does it have to be a natural body of water?"

Derek considers the same thought but his mind goes blank when Stiles finally turns to face him and his lips and nose brush his stubbled cheek, making the boy's breath hitch.

Clearing his throat as he feels his face heat up where they made contact, Derek pulls back slowly. "I'm not exactly sure, but I would assume that it makes it easier to cover her tracks if it is. Water running away from the scene, nothing to linger but the body."

When he looks down Derek catches a small smirk on Stiles' face before the boy looks back at his computer screen, licking then biting his bottom lip as he thinks. Derek rolls his eyes but finds himself following the movement of Stiles' tongue. He clears his throat and shakes his head before focusing back on the topic at hand.

"Oh, what about -" Stiles breaks off mid-sentence and Derek just watches as he opens a new tab and begins pulling up a map of the county where he points at a spot on the screen near the river. "One of the make out points is on a cliff right here and the river runs right underneath it."

"That could work…" But now all he can think about is whether or not Stiles has ever been there with someone. He forces himself to shake it off and head to the window. "We'll figure out a plan later. I'll talk to you tomorrow."

He opens the window and pauses when he's halfway out of it. "I'm sorry… Goodnight, Stiles." Then he's out and running into the woods, checking the perimeter again instead of going home so he can clear his head of all thoughts of Stiles and someone else making out.

THREE

Derek sends Stiles a text the next day to gather the rest of the pack and meet at the loft. He showers quickly and changes into jeans and a Henley before heading into the kitchen to make himself some breakfast. By the time he's grabbing a box of Captain Crunch and a bowl from separate cabinets his phone vibrates in his pocket with a reply. Setting them both on the counter, Derek pulls out his phone and reads the text.

Time? Stiles asks.

Whenever is fine with me.

While he waits for a reply Derek pours the cereal but before he's able to grab the milk Stiles responds. Pick a time, asshole, so everyone can get there at the same time and we don't have to explain twice.

He growls and texts back, 11am. That work for you, pain in the ass?

Milk has been poured and a spoon has been grabbed, everything left on the counter as he picks up his bowl with one hand and heads to the living room, when Derek's phone vibrates in the other.

Yes, the text reads, and I'm not a pain in your ass yet. ;)

Looking down at the text, Derek drops the bowl. It shatters, milk and soggy Captain Crunch covering his feet, but he can't bring himself to move. He stares at the text, trying to remember how to breathe. How to respond, he doesn't fucking know, so before he says something mortifying Derek slips his phone into his pocket and walks back into the kitchen to get stuff to clean up the mess. Once he's cleaned it all up and has sufficiently thought about a response, he digs his phone back out and responds, You are, but when I finally get you back you might not be able to walk right.

Derek waits a bit and as it gets closer to 11 he feels nervous. He hasn't gotten a response from Stiles, which both freaks him out but makes him pretty smug that he left Stiles speechless. Choosing not to worry about it, he just grabs his laptop and watches an episode of Archer to take his mind off of things while he waits for the pack.

The first to show up are Scott, Allison, Erica, and Boyd.

"What's up, grumpy cat?" Erica says as she falls onto the couch and puts her feet into Derek's lap.

Derek growls and rolls his eyes. "Get off me." He moves her feet and stands up. Walking over to Scott, Derek gets a nod in greeting from him as Allison gives Derek a hug and Boyd claps a hand to his shoulder as he passes by Derek to go join Erica.

"Where're Lydia and Isaac?" Derek asks Scott, who shrugs.

"They were studying for Isaac's chem final. They should be here in a few minutes."

When the two arrive Isaac is snickering, so Derek dares to ask why. "Stiles is embarrassed for some reason – and did you know he couldn't even get embarrassed? I thought he was disgustingly shameless – so he decided to take the stairs."

Rolling his eyes, Derek huffs, "Idiot," which gets a nod of agreement from Lydia.

After a few minutes he hears Stiles' heavy breathing just before the door bangs open and the teen flops face first onto the area rug Lydia brought over a few weeks earlier, groaning. "Why in the hell do you have to live in the freaking penthouse?"

Eyebrow raised, Derek stands in front of him with a smirk, arms crossed. "No one told you to take the stairs." He reaches a hand out to help Stiles up.

"Maybe," Stiles gasps, "I'm just trying to keep in shape for cross-country season." He considers Derek's hand before taking it this time.

Derek helps him up and before he lets go he brushes his thumb lightly against Stiles' hand. He turns back to the pack, who are watching them intently. "We've got a problem."

"I'll say." Erica smirks. "There's so much tension here I can taste it. And by tension I mean –"

"NOT," Stiles interrupts, his racing heart pounding in Derek's ears, "what we're talking about." He takes a deep breath. "We've got a siren."

Turning to Allison after growling at Erica, Derek asks, "Does your father know anything about how to catch a siren?"

She shrugs. "I'll text him. We lived in San Francisco for a bit; the bay did always seem a little suspicious to me."

Lydia chimes in, "There isn't much about them in the bestiary, but I could look in some of the other books I've got."

"Awesome, excellent plan." Stiles points at them, grinning. "This is why I love you two, you get shit done."

Derek smiles at them both and turns to the rest of the pack, mostly just the boys. "If you see a pretty brown-haired girl, olive skin, wicked smile, singing while luring a boy to a body of water - stop her."

"Question." Stiles raises his hand. "Since you guys have super-hearing, won't you be more easily affected by her singing?"

Derek nods. "Yeah, but that's why Scott's here." Derek turns to him. "Go talk to Deaton and see what he can do for us."

Scott cocks his head. "Like some sort of herb or spell to counteract her singing? Or at least dampen the effects?" He nods. "Will do."

Grinning at Scott, Stiles claps him on the shoulder. "Look at you being all smart and shit."

With an eye roll at the two, Derek turns to Erica. "Try and find her. Take Boyd and go see the Sheriff. He might have something in evidence for you to smell or he'll give you clearance to go see the victims' bodies at the morgue." They both nod and stand to make their way out. "Meet back here no later than four. If you find something, text or call."

As Lydia and Allison leave, talking about what books they should look at while Allison texts her dad, and Scott and Isaac leave to head to Deaton's, Derek watches Stiles as he rocks on his feet and rubs his hands together. "Sooo," he drags out, "I'm gonna be bait again, right?"

The wolf frowns. "You're far from bait. I keep my word. Especially to authority figures with the power to arrest or kill me. You and I are staying here."

Stiles throws his head back with a groan. "My father put you on babysitting duty? Great, that's great. Even my own dad doesn't think I can look after myself." He runs a hand through his hair, jumbled emotions – embarrassment and frustration – clear to Derek through the emotions and the scent coming off him. "That really boosts the self-esteem and feelings of trust," he snorts sarcastically, leaning against the table closer to the kitchen.

Derek rolls his eyes. "It's a siren, Stiles. What can any of us do to protect ourselves? Nothing. I have to resort to asking help from Deaton in a situation like this. You just have to accept there are some things that I and even you can't protect everyone from."

"Maybe I'll make myself go deaf," Stiles muses, ignoring Derek as per usual. "Then I don't have to listen to Scott wax poetic about Allison, hear Isaac's voice period, or you growl at me all the time. Then the siren can't do anything to me and we can deal with her without anyone getting hurt."

Panic forms in Derek's chest but he remains cool. "Don't even joke about that."

The teen waves it off. "I didn't mean literally, don't get your panties in a twist. I meant like wearing headphones and blasting music so loud it drowns out the sound of her singing. In fact," Stiles smirks at Derek, "I have the perfect song in mind. You want to know what it is?"

Derek growls, "No. Stiles, don't."

The smirk widens before he starts singing, "Every breath you take, every move you make, every bond you break, every step you take, I'll be watching you."

"You're creepy for being obsessed with that song," Derek sneers.

Stiles ignores him again and keeps singing, louder now. "Every single day, every word you say, every game you play, every night you stay, I'll be watching you."

Grabbing a throw pillow from the couch, and Derek does as the name suggests and throws it at Stiles, hitting him square in the face.

This earns him a glare as Stiles splutters and picks the pillow up to toss back onto the couch. "If my singing offended you, you could have just said so instead of throwing things at my face."

Derek smirks and shrugs. "It wasn't your singing that offended me; it was that shit song. You have terrible taste in music."

"Okay, one," Stiles holds up a finger, "my singing is terrible and could make a human's ears bleed, so I don't know how that didn't offend you. And two," he puts up another finger, "I agree that that song is shit, I just take pleasure in torturing you with it."

Derek sighs but then smirks as he gets in Stiles' space and crowds him. "I know you do. Pain in the ass." He full on grins before pulling away and heading back over to the couch to put on a movie to kill time.

"You wish I was a pain in your ass," he sniffs, flopping on the couch next to Derek.

Huffing a laugh, Derek takes a deep breath in and his lungs are flooded with Stiles' arousal and embarrassment. "Yeah, just like you want me to be a pain in yours."

The teen doesn't rise to the bait, though, just sits still – as still as Stiles ever can – and keeps his eyes on the TV, which Derek sees out of the corner of his eye. "Glad we're in agreement - and you're not completely clueless - for once."

Derek rolls his eyes and ignores Stiles, moving as far from him as possible on the reasonable-sized couch. "I hate you."

"Hate you too, buddy," Stiles snorts, amusement and contentment mixing in with his sent and making Derek's chest fill with warmth.

FOUR

When the pack reconvenes they have little to show for their efforts. Lydia and Allison find little they don't already know, Boyd and Erica come up with nothing, but Scott and Isaac return with this sort of wax. Scott explains the wax, which they're supposed to put a little bit of in their ears, is laced with something that blocks out the siren's song. Derek just sighs and pinches the bridge of his nose but nods and thanks them all for doing what they could. They all go their separate ways after that, but come back the next day to finally devise a plan to catch this girl.

"Stiles suggested this make out spot close to the river, where it would be easy for her to get a boy to go with her. Maybe we go undercover - paired off but to keep eyes out, not to make out," Derek says bent over a printed copy of the map Stiles had pulled up on his computer the other day.

"He's talking to you two heathens," Stiles adds, pointing at Scott and Allison, who give him twin looks of innocence, dimples and all making him and Derek roll their eyes. "Okay, I'm guessing Scott and Allison, and Boyd and Erica are going together, and I'm not going with Isaac." The curly haired wolf sneers at Stiles who flips him off. "So Lydia, you and me?"

Derek looks at her as she smiles at her former devotee.

"Actually, I think I'll go with Isaac."

Derek sighs and rolls his eyes at them all. "Fine, couples go together, but I swear to god if you do anything but recon I'll make sure you regret it." He turns to Lydia and Isaac. "Goes for you two as well. Don't care if you are or aren't a thing. Keep an eye out so we can just catch this thing already." Lydia rolls her eyes and Stiles interjects before she can say anything.

"What about you, Der?"

Derek turns to look at him.

"You gonna be able to keep your hands off me?" He winks and smirks.

Isaac snorts and mutters, "Yeah right," earning him another middle finger from Stiles.

Derek rolls his eyes for what feels like the millionth time in the past ten minutes and walks past them, slapping both of them on the back of the head. He keeps walking, grabbing his jacket off the back of a chair and his keys from the coffee table before heading to the door. "Let's go."

Everyone stands and starts to file out. Stiles stops next to Derek, rubbing the back of his head. "I'm guessing we're taking your car, since you have something against mine?"

Derek huffs a laugh and pushes him out the door while the others head down to their respective cars. "It's not the car. It's your driving." He locks the door to the loft and turns back to Stiles, waiting for him to head downstairs.

"Hey, I am an excellent driver." Stiles jabs him in the chest with a bony finger. "It's your driving that's frightening."

Derek rolls his eyes. "Can't handle offensive driving? You're a defensive driver."

"You're damn right I'm the defensive driver," Stiles snorts as he finally turns and starts to head downstairs, "considering I'm always the getaway driver, getting shot at, chased by wolves and other creatures, being attacked by winds created by crazy druids. Would you like me to keep going down the list?"

Derek huffs and just pushes him towards the car when they finally get outside. "Shut up and get in." He walks to the driver's side and slides in, starting the Camaro and watching Stiles narrow his eyes and then shake his head before finally getting into the car.

"Nope, can't think of a good innuendo for that."

Derek smirks. "You'll think of one." It comes out more considerate than annoyed. "Maybe in the shower." He floors the gas pedal and heads to their destination.

Stiles gives a pensive hum. "I always figured if I tried something in the shower with another person I'd fall and hurt myself somehow…"

Laughing, Derek tries to mentally put together one of the many images he has of Stiles falling with one of him wet and flushed. He shakes his head when he feels his cheeks heat up. "I'm sure you would. Unless you're with someone strong enough to hold you up."

Stiles just nods. "Yeah…" he trails off and just stays quite for a minute.

With a subtle sniff Derek nearly chokes on the spike of arousal coming off of Stiles as he spaces out, but he holds it in as he drives even faster even though they are almost to the make out spot.

"Dude," Derek looks over to see Stiles looking at him with raised eyebrows, obviously no longer in whatever world he was just in, "it's still early, we're gonna get a spot, no need to speed. Unless you're planning on getting pulled over by my dad or Parrish."

Derek looks over at him and slowly takes his foot off the gas completely. "Sorry." It comes out through gritted teeth as the smell of Stiles' arousal fades.

"You okay?"

As they pull up to the make out point Derek nods. He parks and just keeps his hands on the steering wheel, refusing to look at Stiles.

"All right…" Stiles trails off, waiting for him to respond but Derek stays quiet. "So brunette, olive skin, pretty apparently. She'll probably come in one of the cars, huh?"

Derek nods. "Not sure which but just kind of keep an eye out." He sighs and relaxes his body a bit, taking his hands off the wheel. A car or two pulls up and he flashes his eyes so he can see inside… Nothing so far.

"I feel like such a voyeur," Stiles grumbles next to him as they continue to watch cars come in. "Though this is like a regular Friday night for you."

Derek growls and turns away from the cars. "I swear to god, Stiles, if you don't stop…"

Of course Stiles chooses then to start humming the same fucking song from their last stakeout, causing Derek to resist the urge to smash his face into the dashboard.

Derek's just about to slap Stiles when he forgets everything as soft singing fills his ears. It's coming from a few cars over. Reaching into his jacket pocket, Derek grabs the small container of wax Scott had given to him yesterday and rubs some into his ears before turning to Stiles. "Stay here."

With that he gets out of the car and looks around to see the other wolves have heard it too. He starts to slowly move toward the voice, eventually getting close enough to see the girl in question lying in the bed of a truck with a boy who has his head in her lap. She stops singing and giggles before talking quietly. "I know there are a few wolves listening. Seems your emissary has done a good job."

Scott had given everyone a small container of the wax he got from Deaton before they split up yesterday. Derek assumes they all had sense enough to put some on in their cars before stepping out to follow the singing.

Derek is close enough to see a smile on the girl's face as she hums between bouts of talking. "You know, I kind of have a thing for tall lanky boys. They are just so adorable. Especially the geeky ones."

A growl builds up in his throat and his feet move forward slightly without his conscious consent. He's the closest, only a yard or so away from the side of the truck. He can get her… At least he can try.

"Oh," she laughs, "seems I've struck a nerve." She giggles, and then slides the boy out of her lap but keeps humming. "I'll let this one go, but keep yours close, wolf. He's exactly my type."

Derek lunges for her, but she runs before any of the wolves can get to her. Growling in frustration and worry, he turns back to the direction of the Camaro only to see Stiles standing next to a different car flashing a flashlight inside and laughing as the people inside scream. Derek rushes for him and grabs his wrist. "I told you to stay put."

Stiles just snorts at him and rolls his eyes, tugging his wrist back. "Since when has that ever worked out for ya?"

Derek gives an outright angry growl. "FOR FUCK'S SAKE, CAN'T YOU JUST LISTEN TO ME FOR ONCE?" The rest of the pack comes up behind him. Scott puts a hand on his shoulder but Derek shakes it off and turns to him. "Take him home and make sure he's safe," he whispers as his chest is still heaving from trying not to outright grab Stiles and yell in his face. Derek walks past him to the Camaro and gets in, peeling out of there.

He gets back to the loft and parks, but doesn't go inside. Instead he gets out and shifts – full-shift this time - and runs into the woods. He needs to find her before she kills someone else. He needs to find her before she finds Stiles. All night he runs, searching but coming up with nothing. He decides to branch out past the pack's borders a bit and search. He's not going to give up until he finds her. He has to find her.

FIVE

Derek has been doing nothing but searching for that siren bitch for the past twenty-four hours. Sometimes the betas come with or let him sleep, but it all ends the same. When the betas aren't with him Derek sends them to keep an eye on Stiles; the thought of losing someone doesn't sit well with him, most of all the thought of losing Stiles.

The betas take shifts, reporting back to Derek after each one switches out. They all say the same thing: Stiles detests being babysat. But Derek doesn't care; he would go to any length to keep his pack safe. Erica gets the biggest kick out of it, Boyd is as indifferent as always, and Isaac makes it out to be the worst thing Derek could have ever asked of him. So he's not exactly surprised when he finds Isaac sitting on the couch playing on Derek's laptop when he gets back after a long search for nothing. The air, however, does all seem to leave the room upon that sight. "Why aren't you with Stiles?"

He grits his teeth, trying to remain in control as Isaac responds. "He didn't want me there, and I certainly didn't want to be there, so we both agreed and I left."

Derek charges at him, Scott choosing now to come out of the kitchen just in time to see Derek pin Isaac to the couch and growl in the boy's face. "Isaac, I swear to god if anything happens to him…"

Isaac whines and yells, "Erica should be there! I wouldn't leave him completely alone!"

Derek texts Erica; when he doesn't get a response in the first minute or two he calls, but she doesn't pick up either. He hangs up and squeezes his phone so hard the screen cracks as he turns to Isaac. "You better hope they are playing a game or something because if anything has happened to either of them I'll-"

"DEREK!" Scott yells to stop his threat.

Derek takes a deep breath but runs out of the loft, not wasting any time. When he gets to Stiles' house he finds Erica knocked out on the ground outside of Stiles' window. Unable to control his anger he full-shifts and howls, signaling the others that shit has hit the fan and the game is on.

He doesn't wait for the pack to show up. He takes a deep breath in and catches Stiles' scent heading into the woods. The girl fucked up; she took Stiles of all people, the one person Derek could always track better than everyone else. He follows the scent at a fast pace, but it's almost stale. He can hear the rushing of the river getting closer as he runs even faster. His heart feeling like it's about to leap out of his chest, causing him to whine in pain. Derek runs fast as he can, hoping he's not too late.

He gets to the river just as he sees Stiles sink under the water. He smells the fear as he watches Stiles struggle to breathe. Derek immediately goes for him but the fucking siren gets in the way. He growls and bares his teeth before lunging at her, going right for the throat, but she throws him off. Boyd comes out of nowhere and tackles her. Derek feels slightly less panicked as he picks up Isaac and Scott's scents not too far behind. He quickly shifts back to beta form and dives into the water, pulling Stiles out and laying him on the bank of the river. He's not breathing. As Boyd, Isaac, and Scott pin down the bitch siren Derek begins CPR.

She starts to laugh. "You're not going to be able to save him. He went so willingly. It was too easy."

Derek growls and looks to Boyd, who immediately puts his claws to her throat and silences her. He keeps up the chest compressions and mouth-to-mouth until he feels a faint pulse in Stiles' wrist. Picking him up, Derek rushes through town wearing absolutely nothing. He guesses Scott called Melissa after he left because she's there with a crash car and a team of nurses and a doctor who begin working on Stiles when he runs up.

Melissa spares him a quick glance and yells inside, "Can we get Mister Hale a pair of pants please?"

She rushes off with the rest of the team and Derek's left standing in the middle of the surprisingly empty ER with a very embarrassed intern who's holding out a pair of scrubs for him while looking everywhere but at him. He takes them silently and slips them on before sitting in one of the familiarly uncomfortable vinyl chairs.

He's been sitting for all of two minutes when that fucking song comes on in the waiting room. Derek stands with a growl and strides over to the nurse behind the desk to ask her to turn the fucking song off with as much politeness he can manage at that moment. She does so, reeking of fear, and he walks back to his seat quietly and sits back down to wait for the pack and the Sheriff to show up.

PLUS ONE

When Stiles wakes up the first thing he notices is the pain: the burning in his throat and lungs that gets worse as he coughs, the heaviness and achy-ness of his limbs. It's also a little hard to breathe, even with the pure oxygen coming in through the tube in his nose. He realizes after that that he's freaking freezing so he pushes the call button and gets some extra blankets from Melissa, who scolds him while she piles them on then helps him get a drink of water.

"You scared the hell out of us all. I'm pretty sure Derek is almost more worried than your dad." Stiles snorts, making him wince as his throat twinges. Melissa smacks him lightly on the arm. "You should get more rest; I'll let them know, for the hundredth time, that you're fine." With that she leaves and it's not long before Stiles does as he's told for once (because he was gonna do it anyway, okay?) and falls back asleep, exhausted.

When Stiles wakes up next he can tell it's mid-afternoon before he even opens his eyes. As soon as he does, though, cracking them only a little against the bright light shining through the window, he can't help a small smile as he sees who's sitting by his bed, nearly asleep. Unable to resist, he starts humming "Every Breath You Take" - until it makes him start coughing that is.

Teary-eyed and hacking into the crook of his elbow so hard it sends an ache through his chest to join the burning, Stiles flails out blindly with his other hand in search of the water Melissa left.

"Stiles," comes the mumbled and slurred response before a warm hand reaches over and grabs Stiles' hand, sending warmth through it and up his arm. "You're supposed to be resting."

"I am," Stiles coughs, "but I can't help if you're a creeper who watches people sleep." He coughs some more before grinning at Derek and adjusting their hands so their fingers are twined together, making it more comfortable to squeeze Derek's. Reaching across his body with his free hand, he grabs the cup of water and gulps it down, soothing his sore throat a little bit.

Derek sighs and squeezes Stiles' hand lightly. "You need to sleep."

"Mm no," he yawns with a raspy voice, clearing his throat carefully and settling back into his pillows as he pushes the button to raise the head of the bed some so he can get more comfortable. "Sleep is for the weak."

"Which is what you are," Derek huffs with a laugh.

"Rude," Stiles mumbles, his eyelids getting heavy. He rolls onto his side, facing Derek, their hands still clasping. The alpha looks exhausted, like he didn't sleep all night. Melissa did say he was worried, but Stiles didn't think he'd have been that worried…

Derek rubs his thumb lightly on Stiles' hand, making it tingle pleasantly. "Yeah, but you like it."

"Yeah," Stiles lets his eyes drift shut, "I guess I have a type."

"S'okay. I do too," Derek yawns.

Stiles hums and his lips barely move as he speaks, his voice quiet. "And what's that?"

There's a sigh from beside the bed before Derek whispers, "Tall, lanky, brown hair, giant nerd, with a nickname that everyone knows and a real name no one could ever pronounce."

"How do...you know?" Stiles snarks brokenly, starting to fall asleep. "You don't...even know...what it is..." Nobody but his dad and Melissa know what it is anymore, not even Scott, who forgot it as soon as he heard it when they were five.

The smile is clear in Derek's soft reply, "'s on your chart."

He had considered maybe telling Derek his name someday, once they knew each other better and bickered for different reasons, but the guy had to go and get it from a stupid medical chart while Stiles was sleeping after nearly being drowned by the monster of the week. "Cheater," Stiles complains with a frown, brow furrowed.

Whether or not Derek responds Stiles doesn't know because after that he drifts back to sleep, their hands still clasping each other tightly.