“They said you were back in town.”
Stiles stood in his threshold, wringing his hands until the skin turned white with the force of it. Derek almost regretted opening the door, but the thundering beat of Stiles’ heart had sent him into a mild panic. The last time Stiles had been that scared, Peter had tried to kill him.
“What do you want, Stiles?” Derek managed. The wet sponge in his hand glistened with paint and glitter from his trashed studio. He didn’t have the energy to deal with high school drama at the moment.
“I think-” Stiles swallowed hard, throat working fervently. “I think I’m killing people.”
Derek narrowed his eyes. The frantic flutter of Stiles’ heart didn’t change. This wasn’t a prank. “I don’t understand.”
“There was this guy, Barrow, and he got into the school and someone left him a coded message to kill Scott’s new girlfriend, Kira,” Stiles said, the words tumbling over themselves in his haste to get them out. “And this keyring appeared in my locker and I didn’t know what it was for until Caitlin mentioned chemicals and I remembered the door to this chemistry closet was unlocked and the keyring was for the door and the message was in my handwriting-”
Stiles’ breathing cut sharply, a hitching sort of gasp that made Derek lean forward. “Stiles?”
Stiles staggered, as if his legs had gone out from under him, and dropped. Derek surged forward and caught Stiles in time to guide the descent, sitting him down against the wall as he shook like a building in an earthquake. But he wasn’t breathing right, and his heart rate was escalating.
“Stiles, listen to me,” Derek said. Stiles clutched at his arms, fingers digging grooves that, if he were human, would surely leave bruises. But he could take it. “Stiles, you’re safe. Do you hear me? You’re safe. You need to breathe.”
Stiles closed his eyes and gritted his teeth, and kept gasping, choking. Derek wanted to shake him out of it. This wasn’t something he could put his fist through, though, and he hated every second of it.
“You aren’t killing people,” Derek said. “You would never hurt anyone on purpose. This isn’t you-”
Stiles shouted, a horrified sound that Derek never wanted to hear again, and shoved at him with more strength than Derek thought possible. Derek shifted, resetting his centre of balance, and evaded Stiles’ flailing arms. He wrapped himself around Stiles’ back, pinning his arms to his sides so he couldn’t hurt himself.
Stiles’ hiccuping gasps beat against his chest as they sat together. Stiles dug his fingers into Derek’s arms, and Derek pressed his face to Stiles’ shoulder, trying to keep his own breathing as steady as possible. He wasn’t sure how long he sat there, with Stiles shaking like he would fly apart at the weakest breeze, but eventually Stiles quieted. His breathing slowed, and Derek didn’t hear the horrible rasping anymore.
“It was my handwriting,” Stiles said. His voice was eerily level. Derek felt hot droplets splash against his arms and smelled the tang of salt in the air. “And I’m losing time.”
“Do you want me to let go?” Derek asked, his voice muffled by Stiles’ shirt.
Stiles’ fingers twitched. “No.”
Derek shifted, dragging his legs around until he cradled Stiles between his knees and held on. “What do you mean, losing time?”
“I have these dreams,” Stiles started slowly. “And they’re so real. I can’t tell when I’m awake. A dream within a dream. Inception, except forever. And I can’t wake up. I can never wake up-”
“When did this start?” Derek asked. Stiles’ heartbeat quickened.
“When we sacrificed ourselves for our parents,” Stiles said. “It’s the darkness. And I tried to-”
“No.” Derek spun Stiles in his grasp and gave him a sharp shake. “It isn’t you.”
“Thanks for the vote of confidence,” Stiles said. His eyes were red, and his face deathly pale. “But I’m not exactly an innocent. I torched your uncle.”
“He may have deserved it,” Derek said. It got a small smile of out Stiles, and Derek considered that a win. He carefully untangled himself and stood, extending a hand to Stiles.
Stiles grabbed it and let himself be hauled up. Derek led the way to his small kitchen, and he poured Stiles a glass of water. Stiles gulped down the glass like he hadn’t drank in days, and set it on the small island. Derek leaned against the countertop, arms folded over his chest.
“I, uh- Shit.” Stiles rubbed the back of his neck, a light flush colouring his throat. “I’m sorry- about that. I had it under control until I saw you-”
“You drove like that?” Derek’s eyebrows shot up. “Stiles, where is Scott?”
“With Kira.” Stiles waved a hand absently. “What was I supposed to do? Call him up and go ‘hey, I’m about to have a panic attack because I might have tried to kill your new girlfriend’? That would go over real well.”
“You’re not trying to kill anyone, Stiles,” Derek said.
“Yes, well, forensics would say otherwise,” Stiles said. “And it’s not like I can provide an alibi for the last few weeks. I don’t think the FBI would accept ‘hanging out with my werewolf buddies running in the woods’ as a valid excuse.”
“You’re not killing people, Stiles,” Derek said again.
“Keep saying it, big guy, maybe your willpower will make it true,” Stiles said. He met Derek’s eyes, and Derek saw the desperation there. “I didn’t know who else to go to.”
“What do you need me to do?” Derek asked. He shifted his weight, and cocked his head at Stiles.
“Wha- Just like that?” Stiles jerked straighter.
“That’s why you came here, isn’t it?” Derek asked. “Because you can trust me to do what you’re about to ask. Because I’m not your father. I won’t arrest you for suspicion of murder. I’m not Scott, who’ll get that kicked puppy look-”
“He really will.” Stiles chuckled despite himself.
“- and I’m not going to institutionalise you. So what do you want from me?” Derek finished.
“If I start hurting people-” Stiles started.
“No,” Derek said. “No, Stiles-”
“If I start truly hurting people,” Stiles said right over him. “I need you to put me down.”
“I’m not going to agree to that,” Derek said. “You’re a human. You said yourself you’ve been dealing in magic. Someone might be controlling you-”
“Derek.” Stiles’ voice was like ice. Derek closed his mouth, his eyes flaring in frustration. “Please.”
“I’m not going to kill you for something out of your control.” Derek lowered his voice and let it sink into the space between them. Stiles held his gaze, unmoved. “You are not collateral.”
“You’re the only one I can trust with this,” Stiles said. “I don’t want to wake up with my father’s blood on my hands. Please, Derek.”
His voice broke, along with something in Derek. Derek stepped closer to the island and set his hands on the countertop. He exhaled harshly through his nose and nodded. “Fine. If there is absolutely no other way to fix whatever is going on with you, then I will not let you hurt anyone.”
Stiles dropped onto a stool like a puppet with its strings cut. He put his head in his hands. “Thank you.”
“It is a last resort, Stiles. We’ll figure it out. Scott’s a good Alpha,” Derek said. “He won’t let anything hurt you.”
“Yeah. I love him like a brother but when he gets his head around a girl…” Stiles shrugged. “Let’s just say I envy his focus.”
“Hey.” Derek shifted closer, forcing Stiles to look at him. “Scott cares about you. He won’t let anything happen to you. New girl or not.”
“Look at you with the pep talks.” Stile smiled, though, and Derek notched another win in his column. “You’re all grown up. Our little sourwolf.”
“Watch it.” Derek jabbed a finger at him. “I can still tear your throat out.”
“With teeth, I got it.” Stiles smiled wider. He glanced around the loft. “Um. Do you want… help with this? Disclaimer, I didn’t do it, but it was kind of a dick move for them to bail without cleaning it up.”
“I could use some help,” Derek said. “The paint is… sticking.”
“Nail polish remover, dude,” Stiles said. Derek stared at him. “It’ll take the paint up, no problem.”
“How do you know this shit?” Derek asked, awed.
Stiles tapped his temple. “Knowledge. Sponge.”
Derek bent to pick up one of the buckets he was using and Stiles’ hand came down on his shoulder. He let himself be maneuvered upright, and Stiles took his jaw in one hand and twisted his head. “What is that?”
“I’ve been marked,” Derek said. “It makes me easier to find when those shadow warrior things come.”
“The what?” Stiles frowned. “What shadow warriors?”
“They attacked the rave,” Derek said. He narrowed his eyes. “Did you leave before that?”
“Yeah, yeah, that was when I found out-” Stiles cut himself off. “The chemistry thing.”
“I’ve got it handled. You have other things to worry about,” Derek said. When Stiles dropped his hand, Derek could still feel the heat of his touch.
Things came to a head much sooner than Derek was prepared for. It wasn’t even a week after Stiles had come to him when Derek found himself floored next to Scott, a broken arm snapping back into place from a blow.
“Stiles! Stiles, stop!” Scott yelled.
Stiles turned his head. His fist was tight in Kira’s hair, and she cringed on the ground in front of him. “I don’t think I will.”
“Stiles, this isn’t you,” Scott said. He coughed and pushed himself to his knees. Derek heard his ribs click as they healed, and then Scott stood. “Stiles, talk to me.”
“Stiles isn’t here right now,” Stiles said. His eyes flashed. “But oh, if you could hear him screaming.”
“Who are you? Why do you want Kira dead?” Derek asked. He pushed himself to his feet.
“I don’t want her dead, I just want her power,” not-Stiles said. He cocked his head. “Unfortunately that means I have to kill her.”
“No! Stiles!” Scott almost howled. His eyes glowed but he couldn’t bring himself to strike at his best friend. His brother.
Derek had no such compulsions.
Derek threw Stiles away from Kira with one strike, sending Stiles spinning to the floor. Kira scrambled to her feet while Derek stalked after Stiles. Stiles whirled, and Derek easily caught the wild punch but missed the knife. Derek jerked as the knife slid home, driving into his lung. Not-Stiles grinned wickedly.
“Stiles is still in there?” Derek asked around blood in the back of his throat.
“And hurting so very deliciously,” not-Stiles said.
Derek shifted his grip, fisting his hand in the front of Stiles’ shirt, and dragged him closer. He caught not-Stiles’ gasp in his mouth as he sealed their lips together. Not-Stiles froze, the knife in Derek’s gut vibrating while it tried to process what was happening, and then the body in his hold spazzed and flailed in a very Stiles-like way.
Derek loosened his hold and dropped to his knees, struggling to breathe through the knife lodged in his ribcage.
“Oh my god. Oh my god.” Stiles- thank fuck- fell beside him and yanked the knife out. It clattered to the floor somewhere far away, and Derek didn’t care because he was falling forward. “Derek! Derek!”
“He’s healing, Stiles, it’s okay.” Scott’s voice came from somewhere above him, but Derek was too busy gagging on his own blood to bother paying attention. Hands turned him on his side so he could spit up the obstruction in his airways, and his lungs filled with air as he pushed out the blood.
When he could breathe again, he rolled his head and met Stiles’ frantic eyes. He was bleeding from Derek’s claws to the shoulder, and Derek touched the injury lightly. “Are you okay?”
“Am I-” Stiles cut off with a hoarse laugh. “You were supposed to kill me, not kiss me!”
“Last resort, remember?” Derek said. He felt so tired. Healing took it out of him, and drowning in his own blood was not one of his favourite things to heal from. “There’s something in you.”
“I know,” Stiles said. His fingers tightened around Derek’s arm. “I know. But I know what it is now. We can fix it.”
“Good. Good.” Derek patted Stiles’ fingers. “I don’t like it when you stab me.”
“I don’t like it when I stab you, either,” Stiles said, his voice hoarse. He threaded his fingers through Derek’s hair. “I did like when you kissed me, though.”
“Yeah?” Derek hummed. “Should do it again, when this is all over.”
“Yeah. I’d like that.”