Sam woke to the sound of soft groaning. He turned towards the sound and found it was coming from Dean. His brother was lying on his back, legs tangled in the sheets, fists clenched, face turned towards Sam. Once his eyes had adjusted to the darkness, Sam could make out the sweat trickling down Dean's temples, matting his hair and leaving stains on the pillow. His expression was pained, as if something was hurting him.
Another nightmare, thought Sam. They'd all had their fair share, but ever since his brother had come back from purgatory he had them almost nightly.
The moaning grew louder and Dean thrashed with his legs, head twitching from side to side, fists digging deeper into the mattress.
Sam was about to put a hand on his shoulder and wake him when he heard a choked "Cas, please." Now Sam understood. He'd known Dean had been having a hard time moving on from Cas, but he had hoped all the booze and one-night-stands had cured him like they always did. Apparently not.
He wondered how long this would go on. It had been 3 months since they Dean had come back and he couldn't help but think Dean was taking his much harder than when they had lost dad. He knew his brother and the angel shared a deep bond, going all the way back to when he'd pulled him out of hell. Cas had saved his brother's life countless times and he'd been a friend to Sam too.
"No… don't… Cas…" Dean made a whimpering sound, his eyes twitching and rolling behind closed lids. He was writhing painfully now; his sheets were thrown off the bed and onto the floor. Sam got up and sat down on the edge of the mattress. He put a hand gently on Dean's shoulder, shaking a little. That only elicited a muffled yell, Dean's back arching off the bed. "No… stop… I'm sorry."
"Dean!" shouted Sam, shaken. He gripped his brother's shoulder hard, putting his other hand on his chest. "Dean!"
His second yell snapped Dean out of it and he awakened with a start, wide-eyed, sat bolt upright and sucked in a huge breath. Still panting, he eyed Sam's worried expression and realized what had happened.
"Dean—"
"Don't wanna talk about it," he snapped, rubbing a hand over his face and through his hair, then turning to reach for his flask on the night stand. He took a swig and stared at his hands, which were shaking slightly, fully aware that Sam was still sitting next to him watching him.
"Was it about Cas?" Sam asked cautiously, as if he hadn't heard anything.
Dean sighed, said nothing, just stared at his hands. He knew his brother would force it out of him sooner or later.
"Yeah," he said quietly.
Sam nodded, not really knowing what to say. "Want to try and go back to sleep?" he said finally.
Dean looked at the digital clock. 5:12 am. He knew he'd never be able to fall back asleep anyway. He didn't want to see Cas tortured and leaving him again.
"Nah, I'm gonna shower, then we hit the road. You good?"
"Uh yeah, ok," Sam said, getting up, giving his brother some space.
Dean headed to the bathroom, locked the door and splashed ice cold water over his face. His dream was still running through his mind. Cas being tortured by the souls inside him, the leviathans, losing his angel powers, finally finding him in purgatory only to lose him all over again.
"Dammit, Cas," he muttered, stripping off his sweat-drenched shirt and boxer briefs and climbing into the shower.