Derek is chasing a squirrel.
It's maybe not his proudest ever moment, but it's also one of the things he likes best about being what he is: indulging in pure, basic instinct. Everything is simple to a wolf, even one with a human capacity for reason. Scott and the others, the bitten pack that Derek has tried to make into a family, seem to think of the wolf as a separate entity, but Derek knows better. Derek knows that, most days, he's more wolf than man.
So for him there's nothing shameful in being more than a little uncivilized, particularly when the moon is drifting full and yellow at the upper edge of the forest canopy, like it's resting there before it makes the rest of the climb into the sky. It's a beautiful evening, late summer and the earth cool under his paws even if the air's still muggy-hot. The heat makes everything move a little slower. Even the squirrels.
Squirrels are tricky, usually, but he's come across this one in a bad spot. It knows it, too, because when it sees him it freezes, trying to blend in to the leaf-littered cover of the forest floor. It should run, but it's left itself too far away from the nearest tree. Derek can hear its heart thrumming so fast it sounds like it's on the verge of just exploding in the little morsel's chest.
Derek wants to know if it's even possible for that heartbeat to go faster. He lunges.
It isn't much of a struggle, because Derek might be big but he's agile as hell, and the squirrel's survival instincts are clearly just not there — really, Derek's doing the squirrel gene pool a favor, here. The squirrel runs left when it clearly should go right, and then it tries to fake him out, dodges right again, but it's too late and the squirrel is never going to reach that tree, because Derek's closing in already, one outstretched paw bowling the squirrel over, its fluffy little tail windmilling as it does its best to keep its feet. (It fails.) It's almost leisurely the way Derek pounces on it, pinning it down beneath a paw that's bigger than its whole body. Derek opens his mouth, triumphant, dives in for the kill and—
And the squirrel says, "Derek," in Stiles' voice.
Derek stops, digs his toes into the squirrel's squishy body to see whether it makes the sound again, but mostly it just looks like a squirrel, pissed off and terrified in equal measure, trying to pry his paw off with its one tiny free fist. It chitters and screeches nonsensically, none of the sounds anything like Derek's name, and none of it sounding remotely like Stiles.
Well, okay, it sounds a little like Stiles, when he's had too much caffeine. But Stiles can't be a squirrel. Stiles is... Stiles is... where is Stiles? Is he back at the house, ready to wait out the full moon with the rest of the humans? And where is the rest of the pack, come to think of it? The sun isn't quite down yet, but shouldn't they be around, if Derek is already running? Derek can't smell them anywhere, can't smell much of anything if he thinks about it, except grass and trees and distant water. He can't actually smell the squirrel under his paw, either.
The squirrel says, "Derek," again, in a voice too deep for its tiny body. Derek squints at it, and it squints back.
Derek can't smell the squirrel, but he can smell Stiles suddenly, like Stiles is right in front of his face, but the only thing there is the squirrel so—
Derek's eyes snap open. His hand clutches reflexively against the bedspread, an instinctive spasm to try to keep the squirrel from escaping, but of course there is no squirrel, just Derek face-down on Stiles' bed, the blankets in disarray beneath him, and Stiles' face right in front of him, contorted like he's trying to hold back laughter. He's crouching right next to the bed, too close; obviously he's been watching Derek dreaming like it's better than television.
Fucking son of a bitch.
"You were whimpering," Stiles says. "And twitching, kind of—" Stiles demonstrates, drawing his hands up right next to his face and wiggling them in an incredibly unflattering impression. It actually makes him look more like a squirrel with a nut than a dreaming dog, though, the little shit. "I thought I ought to wake you up. You know, in case it was a nightmare. And uh, by the way, you seem to be having like a night-time sort of... self-control problem." He smirks, obviously pleased with himself.
Derek frowns, not exactly sure what that means, but frowning is all it takes to figure it out, because his brow's in a not quite human shape and when he runs his tongue around his dry mouth, he feels extra lengths of canines.
He doesn't put them away. "Aren't you supposed to be doing something?" Derek asks, enunciating carefully around his fangs. "Very important homework, can't interrupt for the sake of research, you'll just have to wait, Mr. Alpha Killing Machine? This ringing any bells?"
"Oh, I was done with your research like an hour ago, but I couldn't bear to wake you up," Stiles says. "You look so cute when you're growling in your sleep. Do you always do that? Wolf out when you sleep, I mean? Is that like the werewolf version of morning wood, or what?"
"No," Derek says. "The werewolf version of morning wood is morning wood. Dumbass."
"Hey, it's not my fault every werewolf around me is withholding with the essential knowledge," Stiles says. His pupils have dilated a little, and apparently just Derek saying the words 'morning wood' are enough to get him going a little. He's a teenager, it's to be expected. Derek used to be the same way.
That doesn't mean he's above using it, though. Derek pulls the teeth back in, puts his human face on, then rolls over, stretching out against the bed. Stiles' eyes snap predictably to the skin of Derek's stomach, where his t-shirt rides up. Derek drops a hand there, too, gives his belly a scratch, lets the shirt inch up a little further. Stiles' heart rate edges satisfyingly up.
"What qualifies as essential knowledge in your book, Stiles?" Derek asks, and lazily trails his hand back up his chest, reaches it above his head for another stretch. It feels good, his muscles warming, the bed comfortable. He isn't inclined to get up.
"Well, somebody could've told me you guys dreamed of chasing rabbits, and I would've had a camera ready to capture the moment for science," Stiles says. It's almost an absent retort, because he's still watching Derek's body, obvious and unsubtle.
"No rabbits," Derek says, with a slow smile. "It's too bad you woke me, I was about to put my mouth on you."
"I— what?" Stiles only barely gets the words out, chokes on them. "You were dreaming about—"
"Just getting to the main event," Derek says. He does feel a little disappointed; dream-squirrels are usually more satisfying than real ones, anyway, even the ones that do squeak at him in Stiles' voice. Real squirrels are good for chasing, but they're more fluff than meat. They get stuck in his teeth.
It's worth losing the dream, though, for the look on Stiles' face, the sudden flood of color in his cheeks, the scent of his arousal as his cock begins to fill against his jeans. Derek intends to actually put his mouth on all of that one day, when his own head's screwed on a little straighter and Stiles is a little older, a little more comfortable with himself, a little less genuinely terrified of Derek. Relationships have never been Derek's strongest point, but even he can feel the potential for a spark between them.
He could let it flare now, but the timing's all wrong; that would be a fire that would leave them both burned, and nothing but cinders to show for it. Derek's had enough of conflagrations to a last a lifetime; he can wait for something a little more controlled, a warming fire in the hearth.
So he moves away instead, rolls off the other side of the bed and smoothly onto his feet, picks up his discarded jacket as he goes and snatches Stiles' notes up off the desk, too, gives them a look to make sure he's taking the pages on binding spells and not Stiles' calculus homework.
"Thanks for the research," he says. He can't hear Stiles' dad anywhere in the house so he goes for the bedroom door instead of the window. "I owe you one."
"One what?" Stiles chokes out. He hasn't gotten up, probably because getting up would put his erection on display — he doesn't seem to know it's on display already because werewolf — and instead he sags against the side of the bed like somebody's cut his strings.
"Hm, I guess I'll let you decide what you want to cash it in for," Derek says. He knows Stiles isn't going to be brave enough to make a move, not yet, but... maybe. Maybe he'll hold on to that favor he's owed until he's ready to use it for something a little more interesting than their usual swap of last-minute lifesaving.
It's certainly worth contemplating, even if at the moment it's only in his dreams.