Author's Note: I am going a bit off topic with this one but I need to do this… I've changed the arrangements of events again but bare with me. Derek has already saved Cora and turned into a Beta and is present at the Vets office. He's weak but alive. Also Erica is alive and so is Boyd but they are at Casa De Stilinski cause Boyd was still injured and Stiles nearly died saving him, so she's currently tapped out on power. There will be more to Childlike Behavior later… Gotta angst right now. This is long… I own nothing.

Ice Cold Darkness

Derek stepped forwards. He wasn't going to let Stiles do this. He couldn't watch her die. He couldn't let this happen. He couldn't let her do this. But the look in her eyes was something that he could feel tearing his heart in half. Deaton kept talking.

"It can't just be someone to hold you under, it has to be someone who can pull you back as well." There was a pause. "Lydia you go with Stiles." Stiles stepped forwards her head lowered, eyes glued to her father's badge in her hands.

"No. If it's someone who has to be able to pull me back it needs to be Derek." The whole room was silent for a moment. Derek's breath stuttered.

"No! I… Stiles you can't make me do this." Stiles turned to him.

"I'm not making you do anything. I'm asking you to help me. To help me find the only person in the world who gives a damn about me, the only family I've got left." The room was quiet for a moment.

"Stiles, you know I care about you." Scott said stepping forwards.

"Yeah really felt the love when you left with Deucalion and I didn't hear from you for nearly two days. While I was getting interrogated by you dad because mine's missing. Or when Allison and Isaac went incommunicado for three hours, yeah I get your dad locked you in the vault but you still had your god damned phone. The only person who has actually helped me in the past week is Lydia but… It can't be her." Stiles sounded so sure of herself, Lydia might have been offended if she wasn't so scared. Instead she was just confused.

"Why not?" Stiles shook her head. Her eyes glowed slightly but didn't quite manage to change. She'd been running on what Peter coined Low Battery for nearly a month now. If she wasn't she might have been able to find the Nematon without the need for this but she wasn't strong enough. She'd spent nearly all her energy closing Boyd's wounds and kickstarting his healing enough to save his life. He was still recovering, and she'd spent nearly two days unconscious after that. Derek had been terrified he was going to lose her, he'd stayed by her until the moment she had woken. After that he'd kept her at arm's length but now he could see how bad a decision that had been. She thought they didn't care. He reached out to her, caught her in his arms, held on when she tried to step away. She sighed.

"Derek, Scott and Isaac all have a sense, something that tells them when somethings not quite right. My powers might not be working enough to help right now, but they still tell me some things. It has to be Derek." Derek looked down at her and his eyes flashed blue. His wolf knew it wasn't an Alpha anymore, but it still howled for Stiles. It was set on ripping Jennifer to shreds. The bitch had to die. She'd hurt Stiles, hurt her by taking her father, by briefly tempting Derek away from his Mate. He wanted to bury his head in her hair and stay there where she was safe in his arms. But the full moon was tomorrow night and it was the best shot they had to end this once and for all. And they couldn't do that if they couldn't find and stop the sacrifice. He turned Stiles around in his arms and gently tilted her head back so she was looking into his eyes.

"Stiles you're not asking me to pull you back. You're asking me to kill you. I… I need you. I can't watch another person I care about die." He felt Stiles tense in his arms. There were tears in her eyes as she buried her head in his chest for a moment. Then she pulled back and turned to Lydia.

"Will you still help me?" The redhead froze, tears beginning to spill from her eyes. She knew what Stiles was asking, she was asking if, knowing that Stiles didn't believe that she would make it back without Derek she would still force her friend under the water. Jackson made to step out of the corner he'd been standing in since this all began. He growled at Stiles, she couldn't make Lydia do this. But Derek stepped between him and Stiles a growl of his own slipping past his lips. He grabbed Stiles' hand and spun her around into his arms again. Scott looked like he had some things to say about that but he made no move to hurt her. Instead he did what he'd been wanting to do for a while now. He buried his head in her hair, it was nearly shoulder length now and he barely heard her squeak in surprise. He briefly nuzzled the crown of her head for a moment before fitting his head into the crook of her neck and scent marking her, thoroughly. He spoke, whispering into the skin just below her ear.

"Promise me you'll come back. Because if you don't, I'm coming in after you." Stiles wrapped a hand in his hair and let him hold her for another moment before she nodded. He rubbed his nose against her skin for another moment, not caring that the others in the room were watching, not caring that Scott's eyes flashed at him for a moment. There was no jealousy coming from him, just fear and concern for his friend. Then he stepped back, keeping Stiles' hand in his as long as he could.

"Alright, if you think I'm the best way to get you back then I'll help." Stiles breathed out a sigh, some of the tension that had been ingrained into her shoulders over the past few days melting. Derek wanted to feel proud but he couldn't bring himself to do it as Stiles toed off her shoes. Scott eyed him almost curiously but nodded at Deaton who took his spot behind the furthest tub to the left. Isaac positioned himself behind the tub to the far right and Derek took his que to stand behind the one in the middle. Before she could step into the tub he caught her hand again pulling her close. He knew it might be his last chance to tell her, everything she was to him but the words stuck in his throat and instead a different something came out.

"You know why it has to be me." That wasn't a question, he could see it in her eyes. "Why?" That most definitely was a question, one he was desperate to know the answer to. If she felt the same way he did… But no that was wishful thinking. He wasn't that lucky, but the rosy blush that rose on her pale freckled cheeks told him that maybe, just maybe he was.

"When I get back, we'll talk about it." There was conviction in her voice and her eyes as she turned her hand in his and squeezed before dropping his hand and stepping into the icy water. For a few moments the three sacrifices, for there was no other word for what they were, sat in the water shivering. Stiles could feel her fingers going numb, her teeth chattering. She looked up as Derek placed his large hands on her shoulders. She glanced at Allison and then Scott the two of them nodded and Stiles nodded at Derek knowing that, weakened or not he could still hear her heart going a mile a minute. She nodded again and he pushed her under the water.

She didn't take a breath before she slipped under. It would just take more time. She'd nearly drowned before but that time she'd been saving Derek, not letting him hold her under. There was an irony there she thought as her last breath bubbled out of her lungs and water rushed in.

The irony wasn't lost on Derek who shook as he held Stiles under the water as her body seized before giving in to the water in her lungs. He listened as her heart stuttered and suddenly stopped. Derek let go like he'd been burned, tripping backwards and nearly falling as he stared at the ice that had floated above Stiles' face, so he could no longer see her lifeless empty eyes. He was sure that he would never forget that face, that it would be added to his nightmares of screams and burning. He tried to take a deep breath but didn't quite manage it. He turned to Deaton who was wiping the water off his arms, eyes averted from the tub containing his unmoving protégé.

"How long?" Derek bit it out like every word hurt him and in all honesty they did. Every breath he took in a world without Stiles hurt him. Having watched the light leave her eyes as they slipped closed hurt worse than Kali shoving a piece of rebar through his intestines. Deaton passed the rag to a shaking Isaac who nearly dropped it.

"They should only be under for a few minutes but…" Derek's head shot up a growl building in his throat.

"But what!" Deaton shook his head.

"Things like this are never certain. It should be a few minutes. But it could be an hour maybe two. Magic is never exact, you should know that, spending as much time with Stiles as you do, or at least as you should." Derek glared at him a full out growl slipping from his lips as his fangs slipped out.

"I just had to hold my Mate under ice cold water until it killed her. And now you fucking tell me you don't know when she's going to wake up." The room was tense for a minute. Lydia spoke first stepping out of the corner where she'd been huddled in Jackson's arms tears still streaking down her face.

"Mate?" She asked, and Derek flinched his eyes zeroing in on Stiles. Her fingernails were turning blue, still holding her father's badge in loose fingers. He curled in on himself as he nodded. Lydia knew what that meant. So did everyone else in the room from the looks on their faces. Jackson and Isaac wore twin looks of shock but Deaton looked less than surprised.

"Only a wolf who has found their true mate could be strong enough to survive the transfer of power you used to save your sister. But to be honest I knew from the minute you remembered her. You've grown overly protective of her and you've taken to scent marking her at every opportunity." Isaac nodded.

"I did notice she smells more and more like you but I didn't know what it meant." Derek glared at his shoes could this day get much worse? He plopped down next to Stiles' tub and gently placed his hand over hers. She was so cold. He wanted to snatch her out of the icy water, warm her any way he could, but he couldn't.

Fifteen and a half hours passed. Derek couldn't bare it. Even Deaton was worried. Derek's wolf was howling, on the brink of insanity, only years of practice and control kept him from ripping everyone in the room apart for this stupid idea. There was no way to find the Nematon now, but he didn't really care anymore. He checked his watch. The moon would be rising in a little less than five hours. Kali would come for him then. Good. He didn't want to live in a world without those honey whiskey eyes in it. He stood. Lydia, who'd taken up a spot next to him, between him and Allison a few hours ago, caught his wrist.

"Where are you going?" He shook his head, eyes stinging with unshed tears.

"The moon will be rising soon. Kali will come for me. I'd prefer she doesn't find me here." He didn't want even Stiles' corpse to be there when he died, even though he was keeping his last promise to her, following her into death. Lydia shook her head.

"You should be here when she wakes up!" Derek felt a tear fall from his eyes.

"We both know that's not going to happen. I'm going to keep my last promise to her." He squeezed his mate's limp hand tight for a moment. She was so cold it was hard to believe she'd once been the warmest thing in his life. He couldn't pull her from the now ice free tepid water, not without taking away the miniscule chance that he was wrong. So instead he pulled her hand to his lips and kissed her pale knuckle. Then without another word he left the office, making no sound, leaving like the ghost he felt like.

Stiles felt her eyes snap open as the world around her righted from where she'd been, the Nematon, it had been there since the beginning. She sat bolt upright spewing water from her lungs as she heard two others doing the same, assuring her that Scott and Allison had both made it back as well. They babbled for a moment, that the Nematon had been there from the beginning. That it had connected them all since the night Scott was bitten. But as she climbed out of the tub, shaking slightly as Lydia wrapped her in a towel and fussed she looked around and noticed that someone was missing.

"Wait where's Derek?" Lydia went stiff.

"He left half an hour ago." Stiles felt her mouth go sour with a bitterness she'd never felt before. Then the rest of her sentence bleed through the wall of water in Stiles' ears.

"Half an hour? How long have we been under?" Deaton stepped forwards and handed Scott a blanket.

"Sixteen hours. The full moon rises in four." The three recently dead sacrifices all swore in unison.

Stiles knew that it was foolish, that it was smarter to let Ethan and Lydia go after Derek but the fact that he hadn't waited burned her as she slammed her way back into her jeep, her dad's socks and a shirt of his tossed into her passenger seat. She set her car into gear and sped off down the road not caring about the storm brewing overhead, at least not until a falling branch nearly tore through her windshield. She glanced over her shoulder and regretted it immediately as she felt the wheel move under her hand her jeep swerving off of the road in the storm. She screamed as she saw the tree and tried to slam on the breaks. But it was too late. Her jeep slammed into the tree and the motion jerked her forwards her head slamming into the wheel hard before bouncing her back into her seat. She tried to sit up but her world spun and she slumped in her seat as she felt blood leak down her face.

Derek couldn't believe his luck. He could hear Stiles on the phone with Scott now. Asking him to bring a ladder when they came to rescue them. Derek snatched a sturdy looking ladder from the side wall. He and Scott took off. The ground around the familiar tree stump was partially caved in but Derek didn't care he leapt over to one of the largest holes in the ground and lowered the ladder into it. He could smell blood and that set his wolf on edge he scaled down the ladder as fast as he could. He spotted her before he saw anyone else in the room. But all he saw, all he really cared about was her. He rushed forwards and pulled her out from under the low ceiling. She brought her father with her and ushered him up the ladder. Derek hadn't released her hand. The others slowly made their way out their way slightly hampered by Stiles and Derek. Once everyone was safe Derek gently checked the wound on Stiles' head it was still bleeding sluggishly. He gently brushed her hair out of her face and stole a touch of her pain. She glared at him. He frowned.

"Why weren't you there?" He knew what she meant, he knew that Lydia had been right, that he should have been there when she woke up. He leaned forwards.

"I thought you weren't coming back to me. I was… I was going to keep my promise." Stiles thumped him on the chest.

"You're a dumbass." He smiled.

"And you're safe." He leaned in and began to scent mark her again, covering the faint stench of death with his own. He let his teeth drag over the unmarked skin of her neck, right where it met her shoulder, where he could feel her pulse pound under his tongue. Then the mood was shot in the heart when the Sheriff leaned over the hole in the ground and cleared his throat loudly. Derek jumped back as much as he could. His ears had gone bright red and Stiles wasn't faring much better. She glared up at her dad, a look that could only translate between the two of them as the Sheriff raised an eyebrow and Stiles rolled her eyes sighing as she began to climb the ladder. She glanced back over her shoulder and smiled warmly at Derek.

"You coming, Sourwolf?" Derek let a small smile slip onto his face as he began to climb the ladder after her. Maybe now everything would be alright, he thought as Stiles slipped her hand in his. She glanced around, daring anyone to say anything. Her father sighed and threw an arm around her shoulder as they all made there way away from the large broken tree stump, all trying to get their story straight, Jennifer would take the fall for all of this. It was all her fault anyway, and the dead could not defend themselves. Derek was just happy the pack, Scott's now he realized as the new made True Alpha slipped easily to the head of the group, was alive and well. He had to leave Stiles at her broken Jeep but she was with her father, safe for the moment. And they still had to talk about everything between them, those things that had gone unspoken for far too long.

But they would have time for that later. For the moment he was content to pull her hand to his mouth, gently and lay a soft kiss to the back of her hand. The bright red blush on her cheeks made up for her fathers examining glare. He glanced back at her as he and Scott left to deal with Deucalion and Jennifer's body. Scott sighed and glanced at Derek.

"You really like her huh?" Derek sighed.

"It's a little more complicated than that but yes. I do." He was surprised it was so easy to submit to Scott, to tell him what he'd been fighting against for so long. Scott smiled.

"You better treat her right, or I'm gonna rip your throat out with my teeth." Derek laughed as they headed back into the brewery.