Dean knows he has to leave. He can't protect the angel here, not when the Leviathans have a plan he doesn't comprehend and he has to try and stop them. He can't take him away, where the angel could get hurt when he tried to help. And he would try to help. Cas knows it too, though his stare is blank and haunted, and he flinches at even the softest noises. He looks afraid, something Dean doesn't ever remember him being.

"Cas?" Dean speaks softly, hoping not to frighten him. Cas looks up, his face crumpled into a terror so deep and complete it manages to scare Dean. Sam is outside the room, back in normal clothes and standing straighter than he has in weeks. The angel in front of him is in all white, and it adds a glow to his pale skin, and it's how Dean always imagined angels would look. His hair is messy again. Unlike the combed back perfection Emanuel presented, this is windswept and erratic. A style Dean associates with Cas. Not Castiel, Emanuel, Leviathan, man, or anything in between. This is Cas.

"Dean?" The voice that responds is high-pitched, gravel-tinged with panic. Dean wonders what Lucifer is saying to him. "You're leaving?" It's not really a question, but the angel adds it to make it hurt a little less. Dean bends down slightly to meet Cas' eyes, the angel sitting on a plain white bed, staring straight ahead, with his hands folded delicately in his lap.

"We have to, man," Dean says and it sounds just a bit broken, even to him. Maybe the angel can hear it too. "I need to keep Sammy safe, need to keep you safe. Can't do both at once." He hates admitting it, but he says it anyway. Cas flinches from something in the corner of the room, the action so shocking Dean steps back slightly. "What?" he asks, praying he can help.

"Lucifer was known for his persuasive techniques," Castiel whispers, flicking his eyes up to Dean and somehow the hunter knows he's not seeing Dean's face. He's seeing his fallen brothers. But Cas is pretending he can. It makes Dean smile. "He says you have not forgiven me."

Dean is silent for a moment, tracing his eyes over Cas' five o'clock shadow and eternally chapped lips and the anxious way he looks at the hunter. "I hadn't thought I'd be able to," Dean admits slowly, hating the crushed look Castiel adopts. "But, man, there isn't anything to forgive." The moment between them is slow and eternal.

"What do you mean?" Castiel sounds coherent, and maybe he's able to push off Lucifer for just a few moments. Like Sam could ignore it before the sleep deprivation. Dean sighs, sits next to him, the too-firm bed dipping with the added weight. Castiel doesn't even wrinkle the sheets beneath him.

"Man, I taught you right from wrong," Dean says. He rubs a hand over his bright green eyes, knowing if he keeps talking they'll be ringed in red. "I showed you how you got things done, how you fought for your cause. All you knew was making deals with demons when it was necessary wasn't that bad, and following your gut was always right. How could I hate you for that?" The question is rhetorical, but Cas could never understand the subtle inflections in a human voice that change the meaning of a sentence.

"Because I fell from a righteous path, I attempted to carve my own version of a world better left to its own devices. I am no better than Lucifer," Castiel says, and the answer sounds almost practiced, rehearsed, like he's subconsciously been waiting for this conversation.

"No," Dean says, and it sounds a little too forceful, a little too harsh. "You wanted to help. You've always wanted to help." His voice breaks on the end; he coughs to cover it. The angel catches it anyway.

"What I did to Sam…" Dean doesn't let him finish.

"And look where you are now," the hunter wants to fix Cas, fix everything, he wants to build the world back from the ashes and erase the shadows. Except for the flicker of wings that stretch from Cas' shoulder blades, those can stay.

"I destroy everything," Castiel whispers, looking away, and Dean can guess he is repeating words Lucifer is hissing in his ear.

"You didn't destroy me," Dean says softly, staring at the ground, his hands clasped in front of him. Castiel looks up, shock and confusion and life in his endless blue eyes that draws Dean to the edge of his own world. "You rebuilt me. You raised me from perdition, remember?" Dean says, leaning closer, his knee touches the angel, and it's all flooding back. Every mile-long gaze and burning fire and confusion and moments when they were alive like heroes in storybooks were. They had something to fight for, then. They had friendship that blurred the lines of humanity and war, realms of Heaven, Hell, and Earth brought together.

Castiel smiles, something Dean has never really seen before, and something he will never forget. The angel and the human share a moment of silence that transcends the agony that constantly surrounds them, and maybe Lucifer is quiet now, for just this length of time.

"When the little Devil on your shoulder starts talkin' again," Dean says after a moment, pulling them back, meeting Cas' eyes like he hadn't in a long time, where they were friends again. "You just think about Chastity."

"The condition of purity?" Castiel asks in confusion, drawing a grin from the hunter that feels foreign on his lips. He shakes his head, a rough chuckle escaping his lips.

"No, man. The prostitute whose father hated his job at the post office," Dean elaborates, watching recognition shoot into the angel's sky colored eyes.

"Why would recalling a den of iniquity protect me from hallucinations of my brother?" Cas asks, his head tilting in that perfect Cas way.

"It won't," Dean answers, staring at him. "You gotta remember that 'last night on earth' and you gotta know I meant it when I asked you to never ever change. I think about that night a lot," Dean admits, staring past Castiel and into the wall like there is something interesting written there. "One of the best nights of my life."

"I believe it was one of mine as well," Castiel admits a moment later, and their shared friendship seems deeper than even they can comprehend. "Though traumatizing is also a word I would use to describe it."

Dean laughs, is nearly bent over with it, slapping a hand on the smaller man's back and he can feel the vibration of his own laughter from his chest to his hand to his arm to his own heart. It weighs heavily and lightly at the same time, a touch that means more to both men than they can ever say out loud.

"I missed you," Dean says after he's calmed down, and he meant for it to be said flippantly, but it comes out truthful, heavy. Castiel meets his eyes, and Dean can see the beginnings of anxiety rising again in his eyes, knows Lucifer is working his way back into his consciousness.

Dean pulls Cas close before he's completely sure of what is happening, is crushing him into a hug that is foreign to both hunter and angel. Cas falls into it, wraps a loose arm around Dean's slim waist, the hunter hasn't been eating very much, too distraught by his brother and by his grief. Dean's grip around his back is as firm as it is unyielding. For a moment they are caught up in chasing wind and Angels that reside on the Moon, where nothing can touch them and they are safe. They rest on the dark side of it, and light does not intrude on their guarded safety.

"I'll fix this. I swear, Cas, I'm gonna fix this," Dean whispers, his voice weaving in and out of Lucifer's musings, Castiel's head must be so crowded. The angel's body shudders, and Dean pretends like he doesn't feel wetness on his shirt. He thinks Castiel would be grateful. "In the meantime, you think about Chastity, and how you got a friend out there, tryin' to help. Always tryin' to help."

Dean hopes his words are not lost on the angel, and that Cas can pick up the nuances in what he's saying. Castiel's grip around his waist tightens for a moment, and then slips away. The air is cold on Dean's back, but he pulls away, staring at blue eyes tinged with red and wondering if he could ever find poetry, a metaphor great enough to encompass what those eyes mean to him.

Dean doesn't have a good track record with friends. But he wants to keep this one almost as much as he wants to go back to the cemetery outside of Kansas, where Sam jumped into a hole with the devil inside of him, and fix things. He wants to go back and stay by the angel, help him in the fight, stay close, stay away from the civilian life that consumed him for a year. A year that led Castiel more astray than ever.

"You have to go," Castiel says, and his voice is back to low gravel, old times when the sudden sound of it spooked Dean and the angel was always too close to him. Memories flood back to Dean and suddenly they're runaways again, counting stars and states that blur behind them, as they run from the world and try to save it all at once. He smiles, it falters, it drops. He's back in the mental hospital, Cas is not wearing his trench coat, and he's too pale and he's starting to sweat with the effort it takes to keep Lucifer back.

"Yeah," Dean says softly. "Yeah, I have to go. For now." Dean stands, his spine pops with the movement. He feels old. He never thought he'd make it to his thirties.

"You will be back?" This time the question is real, and it's a knife in Dean's stomach, twisting and biting and tearing. He looks down at the angel, who is in the same position he found him in, hands folded neatly in his lap, staring at the wall blankly.

"I promise." He means it. He really, really does. He hopes Cas can tell. "Cas…I'm real glad you're back. Not just for helping Sam," he adds quickly, his eyes burning and searching and real. "Things haven't been the same without you, buddy."

"I hope to return one day," Castiel says softly, but his voice is growing distant, clouded out by his own fear, his own panic rising again as Lucifer takes hold of his veins and claws into his mind. "I hope I can redeem myself to you, Dean."

He keeps saying that, like he hasn't already fixed everything by just being there. And being so willing to throw himself under a bus in Dean's name. It reminds Dean of those stories he sees on those ASPCA commercials, where the puppy is kicked over and over and over again and it still comes back to its owner, still loves him. Cas is the puppy.

Dean is the owner.

He feels like he might throw up.

"No. Cas, I hope I make it up to you," Dean manages to choke out, and he hopes his words are falling from his own lips, to Cas, and not from Lucifer's. The angel meets his eyes again, nods like he's been given a mission. Dean puts a hand on his shoulder, like the angel had done to him when pulling Dean form the confines of Hell. His fingers slip off of the white cotton as he walks away, throwing a long look over his shoulder. "Bye Cas." He says it and he wishes he didn't have to. But Dean knows Cas would only get hurt if he came with him. And he doesn't want that. He can't take that.

"Goodbye Dean."

The door shuts behind the hunter, separating him from his angel once again. At least Cas is kept on the dark side of the moon, where he can be hidden away, protected, cherished and safe. His wings are folded and content, though his mind is assaulted by his brother's words, his hands are folded in his lap, and his eyes are not so consumed by panic. The hospital is his moon, Dean thinks as he joins his brother and begins to walk outside, into the light that leaves them vulnerable. He doesn't want to leave, but his heart is lighter as he does it. He's okay.

And he'll make sure Cas is too, or he'll die trying. Because this angel doesn't belong on the moon, separate from reality and duty and the light he is made of. He needs to take on the world and all its faults. And Dean has to do better to guide him, to teach him, so that both of them can see the world for what it is. To learn right from wrong together, relearn the patterns of stars over their heads, state lines as he travels by pavement instead of sky. He belongs next to Dean.

And he's not going to let him slip away again, not going to let him fade back into the darkness. He's going to save this one person, this one innocent beautiful being that doesn't deserve the pain he suffers. Dean's going to do something right. And he knows leaving is part of it, though he hates the concept with all his heart. The handprint on his shoulder burns almost pleasantly, and as he drives away, he can pretend that his angel is wishing him luck and urging him on and saying goodbye, all at once, from his perch on the moon, with stars wrapped around his wings, shedding light on shadows that can fly.