Derek growls at the man before him; he’s a grotesque thing to look at, a corpse inhabited by a roaming, revenge-seeking soul. The body’s face and limbs are distorted, changing to accommodate Peter’s true form, but still retaining the body’s original structure. The face is uneven, the flesh tearing as it stretches to fit Peter’s larger, longer skull; the same goes for his arms and the clothes. Derek can see more muscles and bones as the arms and shoulders and knees creek and bend and rip as they stretch. He rarely feels helpless, but in this moment it’s suffocating him.
“Your fear,” Peter licks lips that aren’t actually his, “is intoxicating, little nephew.” Peter doesn’t move any closer, instead pacing in an even line before Derek. “You may be alpha,” he sneers, “but not for long.”
“How do you know you’ll even get your powers back?” Derek snarls, fruitlessly fighting against the silver restraints binding him to a chair. His breath is falling short, he’s taking too much energy avoiding succumbing to fear.
Peter tsks, fingers idly tracing the curve of his own morphing jaw. “Regardless of the power, I will inherit your position, and your influence over the pack.” Peter licks his lips, shuddering with delight. “I can taste it now.”
“Like hell,” Derek snaps back, bearing his teeth.
“And you know what else I’ll inherit?” The grin that Peter flashes him is disturbing—the teeth, as they shift to become Peter’s old teeth, first die and disintegrate in his mouth, turning them a sickly yellow, brown, leaving unnatural gaps. “I’ll get him, finally.”
Derek struggles harder.
“Oh, poor thing,” Peter steps closer now and taunts a hand through Derek’s hair. “Scared of losing him? He’ll submit to me so readily, because he knows it will keep everyone else safe. I’ll be the first to touch him, to mark him, tobreak him. And then I’ll put him back together again, and keep him for myself.”
Derek lets out a whine, emotions he hasn’t had time or opportunity to confront filling his chest and choking him up.
“I’m sure he tastes divine. He would look so… pretty covered in scars. I’d wait to turn him, until I’m sure he would never leave me. Then I would bite him everywhere, harder, I would savor his blood.” Peter looks manic in the dim lighting of the basement.
“You won’t be able to!” Derek rocks the chair, only succeeding in burning deeper wounds into his skin.
“You don’t know that. Regardless,” Peter licks his lips again, “he will be mine, and you will be dead.”
“He would never.” Derek retorts, but it’s a lie, an obvious one. Because Peter knows Stiles well, knows him terrifyingly well, and the fact that Stiles would put himself in the line of fire for the pack is so achingly true. “He would neverlove you.” Derek grinds out, because Peter could never take that from him. Stiles may not be fully aware of what it is, but it’s there, a small flame inside him that Derek can feel, and will, until the very moment he dies.
Peter smirks. “Maybe not. But I don’t need love.” He says simply, but there’s a light in his eyes that tells Derek he hit some sort of nerve. “Never mind that, though. I think it’s time to take care of you.”
Derek opens his mouth to snarl, to say something else, possibly to cry because he doesn’t see himself making it out of this alive, but Peter falls from looming over him to a mess of limbs, akimbo and bloody, on the ground. Stiles stands over him with a hammer in hand, face specked with blood, clothes too. He pants, tears in his eyes as he brings the hammer down again, right into Peter’s temple.
He throws the hammer away from him, shaking violently as he retrieves the keys to the silver shackles from a nearby table. Stiles crouches by Lydia for a second, petting her hair, then moves over to Derek, key in hand.
It isn’t until Derek is standing, rubbing at his wrists, that Stiles speaks.
“I.. Lydia sent me a message. I don’t know—I don’t know when but she said you needed help and I came,” he gulps in air and swallows, and wipes at the tears on his face—which only spreads the blood around. “I came as soon as I could because Scott got shot and I didn’t have anything and I just grabbed a hammer upstairs and came down as quietly as I could because I—I wasn’t sure, if he would hear me, or what would happen, or if he was still in Lydia’s body because I really really wouldn’t have been able to handle that and..”
Derek reaches out and pulls Stiles to his chest. It was true, Stiles had been quieter than Derek had ever known him to be, since Derek hadn’t even known Stiles was approaching. And neither had Peter.
“I..” Stiles seems to have run out of words and simply winds his hands into Derek’s shirt. “Shit.” He says, brinking on a laugh.
“We’re okay,” Derek says, “we’re going to be fine.”