He had known that it would be bad, but Castiel was honestly surprised at just how quickly his world crumbled. From the moment he took Sam's delusions into his own mind, Castiel was disconnected from everything. Lucifer was speaking to him in Sam's voice, and he couldn't be sure what was real, what was reality twisted into painful unreality, and what was made up wholesale.

Even the walls of the hospital melted away. Castiel was everywhere and nowhere. Rachel was dying at his feet. Balthazar was falling under his blade. His psychosis knew the depths of his guilt, and it dragged every piece of it up to place it before his eyes again and again.

And Dean was there. Dean was always there. Sometimes he spoke, his words more cruel than the real Dean could ever have been capable of. Sometimes he was kind, which made it all the worse when his face morphed back into Lucifer's to laugh at the hope that had sprung up in Castiel. But mostly, he watched. Every terrible thing that Castiel had ever done scrolled past the two of them like a hellish slide show, and Dean watched and judged.

The rules Castiel made for himself came to him almost immediately. Do not speak. A careless word could betray Sam and Dean to their enemies. Do not move. A careless action, with his powers, could kill. It was better not to rise to the bait of the images playing out in front of him. It was better to be silent and still.

He kept to those rules when he found himself back in the hospital room, his clothes and coat replaced with a white patient's outfit. He was sitting on the side of the bed. Dean was kneeling in front of him.

"Cas?" Dean was saying, "Cas, can you hear me? Come on, man, just give me something."

It wasn't real, Castiel told himself. He remained motionless.

Dean put his hands on Cas's knees with a heavy sigh. "Okay," he said, sounding so much like the real thing that Cas felt his heart clench, "Okay. I don't know if you're listening, but on the off chance that you are, I've got some things to say. Here goes."

He took a deep breath, gathering his thoughts. It wasn't real, Castiel tried to remember, but it was so difficult when Dean's fingers were tightening over his thighs.

"We can't take you with us," said Dean, his face twisting as if the words were knives in his gut, "We… we can't. It too dangerous, and we can't protect you when you're like this. No one knows you're here. And in case someone figures it out, we're, uh… we're leaving Meg here to watch out for you. I know. I don't like it either. But I think I've got it all worked out. She can't touch you, not without us giving her up to Crowley. So you'll be safe here. You'll be safe."

Dean's head bowed down then, his forehead resting against the backs of his hands. A few deep breaths later, he continued, "Safe isn't enough. I don't know what's happening in that head of yours, but I know it can't be good. You don't deserve this. Just try to remember that. What you did for Sam… I'm still trying to figure out a way to thank you for that, and nothing's good enough. Look, I don't know half of what you did while you were off playing God, and I guess I should care about it, but I don't anymore. I don't care what you did. As far as I'm concerned, we're good."

If this was a trick, it was the cruelest Lucifer could possibly have planned.

"Did you hear that, Cas?" said Dean, his eyes seeking Castiel's desperately. Castiel didn't even move enough to meet his gaze. His eyes remained fixed on the wall behind Dean's head. "I forgive you. You asked me for that a long time ago, but I wasn't ready to say it then. I'm saying it now. I forgive you for all of it. But I guess this isn't the first time I've waited to say something until it was too late."

Dean swiped a hand across his own cheek. Was he wiping away a tear? Castiel almost reached out to comfort him, but then he reminded himself that it wasn't real. He had his rules. Silent and still.

Another deep breath, shakier this time, and Dean spoke again, "Okay. Listen up now, because this is important. Even if you didn't hear anything else I've said, you'd better hear this: I will come back for you. I promise you that. When all this is over, I will come back for you. Even if I…" And here Dean stopped, choking on the words as if the mere possibility of what he was about to say was too much to contemplate. "Even if I can't fix you. Even if you never get better. I will find a way to take care of you."

He gripped Castiel's knees, white-knuckled, as he said, "I will not leave you here alone."

It wasn't real.

But if it was…

If it was, then he had to say something. He could break his rules just this once. Just in case.

Castiel's eyes flicked down to the face that stared up at him, full of pain and hope. "Dean?" he said.

Dean was standing in an instant, his hands on Castiel's face, searching his eyes, pleading. "Cas?" he said, his voice shaking, "Cas, are you with me?"

He couldn't say all the things he wanted to say, not when the Dean in front of him might in reality be a doctor or a demon or no one at all. But one short sentence, one little promise, could not possibly do any harm. So he said, "I'll wait for you."

Dean's arms were around him then, a crushing pressure on his shoulders and a desperate grip on his clothes. His face was buried in the hard line between the stiff collar of Dean's coat and the soft warmth of his neck. And because this was probably his last chance to do so, Castiel raised his arms and returned the hug, holding Dean's standing form awkwardly against his own sitting form as well as he could.

He couldn't tell if the moment had lasted for seconds or hours. All he knew was that Dean was gone, and the mental torment had started again. He was alone and lost inside his own mind with no chance of escape.

But he held tight to Dean's promise and the sensation of strong arms wrapped around his body. They would sustain him through the next however-long he would spend in the prison of his psychosis. No matter what happened to him now, he could at least take comfort from his last conversation with Dean.

Because it had been real.

Probably.