Dean felt sick. He could still almost feel Castiel beating him to a pulp and while it didn't hurt as bad as having Lucifer beat the crap out of him, it still hurt more than he could honestly fathom, and the fact it was his friend - someone he considered family - made it even worse. Then Cas just up and left, and Meg was... well, dead, as far as Dean was sure, and now he was left with the stark realisation that Sam may well not survive the trials.
Well, that was one thing he was damn well going to avoid if he could. He'd told Sam he'd carry him and if that meant him literally carrying Sam through the trials, he'd do it even if it broke him to. He wasn't letting Sam die, not again.
It took a while for Dean to calm himself down as he paced around his own room, but eventually he headed for Sam's room. He was really glad they'd chosen separate rooms, it gave them both breathing room, it made things easier. Knocking the door, just once, he opened it up, peering in.