Part 2 of the Ruined series.

"You risked everything to save your father," Derek says, as he traces his fingertip down the length of a fresh scar on Stiles' inner thigh, one that bisects three other, smaller ones. It's still scabbed over, a stark contrast to all the others. They're older, pale and silvery. "You need him. But he needs you, too. Do you want him to find you dead one day?"

Stiles huffs. He barely moves, just tips his head to the side, looks down at Derek with his head pillowed on Stiles' naked thigh. "You're being over dramatic. It's nowhere near deep enough." He lifts his hand, drags his fingers lazily through streaks of come on his stomach. It's been a couple of weeks, and most of the time what Derek does to him quells the panic. Derek can't be with him all the time though.

"You could slip," Derek whispers, pressing his thumb against the wound that was barely more than a scratch, only deep enough to bring blood welling to the surface, only enough to spill over and streak down the inside of Stiles' thigh, to his knee, to drip onto the floor and prove in a couple of tiny dots, that Stiles was still alive. "An inch. That's all it would take, on you." He looks up, meeting Stiles' eyes. "What does it feel like?"

Stiles snorts. "Like being cut. What do you think it feels like?"

Derek shakes his head. "Not that. The darkness. The beacon thing."

Stiles turns his face away. "I was dead. It wants me back. I don't even know what it is, but it wants me." He looks back, with narrowed eyes. He doesn't know if he trusts Derek, doesn't need to trust Derek for what they do together, because if it wants him bad enough, there's nothing Stiles can do to stop it. "Why do you want to know?"

Derek sighs and lifts himself off of Stiles. "I'm interested," he says, and then puts his hand on Stiles' shoulder, flips him into his stomach, and Stiles just goes with it. He slides onto Stiles' body, lays on him, heavy enough to squeeze the air out of his lungs and make it hard to breathe. His cock is only a little slick when Derek pushes in, and Stiles hasn't had much prep. He likes it that way. He doesn't have to think, he can just focus on the hot throb deep inside. "I worry about you, Stiles. I care." The words are warm and hoarse in Stiles' ear. "I don't want you to die." The palm of his hand is a painful weight in the middle of his back, and his thrusts, hard and punishing, come before Stiles has had a chance to adjust.

"It's trying to squeeze the life out of me," Stiles rasps, then gasps for breath. "It's always there. I don't wanna die, but it's trying to stop my heart from beating. I can't stop thinking about it, about how one morning my dad's gonna find me cold and it's gonna kill him, Derek—"

Stiles reaches back, desperate to find some part of Derek to hold onto, to ground him, because his head's spinning. Derek grabs his wrist, grabs the other, pins them to the mattress above his head. "Shhh," he says, and he's still moving with slow, but deep thrusts into Stiles' body. "I've got you." He holds both wrists with one hand, lays his forearm across Stiles' back, pressing down with his whole weight.

Stiles can hardly breathe, but he can feel his heart pounding against the mattress, fast, but hard. Strong, like it's pushing back against the black band around it. "Yeah," he says. He's dizzy, but it's not panic. He's warm, and he feels alive, like when he feels the pain of the blade slicing into his skin, like when he watches the blood flow, red over pale skin, watches it hit the floor and explode out into tiny stars.

Blood doesn't flow out of dead flesh like that, and dead hearts don't beat, not like this, not like drumbeats in his ears, in his temples. "Derek," he gasps, and it's the final word, the only word he knows, but in it is a plea for help, with it he begs Derek to never, ever, stop. "Derek—"

"I'm here, Stiles," Derek says. "I've got you."

Stiles sinks into it, sinks into the deafening thrum of his own heart, sinks into the pulsing ache inside him. He loses himself in the gentle buzz of not enough oxygen to his brain. Closes his eyes against the darkness swimming at the edges of his vision, sees the inside of his eyelids painted red and associates the color with Derek, wrapped around him, holding him and keeping him safe.

He trusts Derek to keep him safe.