They're in the truck, heading towards the place where he will die. Where he will lay down his life for a man who dies seconds after him.
Dean gently takes the unopened pill bottle from his hand, drop it to the floor of the vehicle where it mingles with the other trash and broken things that litter the space.
He pulls them over, Dean switches to the driving seat without a word, waiting for Cas to climb back up on the passenger side. Holding out an arm he draws him in close, with all the gruff affection he can muster. He feels Cas's head rest against his shoulder, hair warm and tickling on the places it brushes his neck.
The truck smells of dusty upholstery and sweat and Cas's strange incense odour. He doesn't smell like sex though, which is nice. His slight weight is almost like that of a teenage Sam, warm and young and easily defended – when in fact he is none of those things. He is cold and ancient and fragile. Teetering between life and death.
But right now Castiel doesn't feel like that.
He feels safe, wanted, loved. For the first time in an unthinkably long time, he is secure and almost comforted by the rise and fall of Dean's chest under his cheek.
"I'm sorry." Is what Dean says, after a while.
"I know" Castiel strokes long, calloused fingers lightly over the fabric of Dean's shirt. "But you shouldn't be. We are where we are." He realises something. "You haven't started this yet."
"I can change it." Dean sounds resolved but surprised. He drops a light kiss to the top of Castiel's head, brushing over his flattened, soft hair gently. The move is a shock to them both and a breathless silence stretches between them. "What if we just end up here again?"
"It's not so bad" Cas's voice is nearly dreamy, lulled and warm from contact and the trucks heating vents. "Not right now."
"You don't miss being an angel?" Being better than this?
"I miss you." Cas murmurs "You're different now, I liked you, before."
"You don't like me now?" His arm tightens, trying to shield Cas from...well from everything, himself, his influence, the hundred choices that led them here.
"I love you. I have to like you...but it's hard." He leans up, brushing a rough, bristly kiss to Dean's jaw. "Just...don't ever change, ok?"
Dean climbs out of the truck and together they walk to Castiel's certain death.
Sometimes, even though Castiel is fighting a war, even though he's an angel and a leader...he needs something, for himself.
He was human, however briefly, and because of that, he has a heaven.
It's a small heaven, a brief memory that isn't even his, but someone else's.
In the cab of the truck, Dean and Cas press together, oblivious to the Castiel that sits beside Dean on his other side, angelic and unmoving. Beside the memory-Castiel, an identical man leans against the window, watching the couple embrace with rapt attention.
He catches the eye of the angel.
"It'd be nice wouldn't it, if we'd had...more, of this?" He sighs, then smiles. "It's more than I thought I'd be going out with anyway."
Angel Castiel rarely speaks, he just shares the space, the memory. Watching Dean press a hesitant kiss to the face of his weakened, debauched self.
Today he says, "Yes, it would."
His other self replies, "You could you know."
It's this heaven that he fights for. This tiny sanctuary that his future self has found after so long.
And because one day it will be part of Dean's heaven too.