He needs to be numb. He needs to not feel anymore, and maybe to never feel again.
It's a desperate scramble for the first thing he can find to do the job - needle, pill, powder, he doesn't fucking care.
Soft fabric catches on his knuckles, burning him like Hell's raging inferno because it's Dean's shirt, and fuck if Dean didn't make him promises he can't keep, not now.
The shirt hits the wall soundlessly and slides back down to the floor, covering his semiautomatic - lying exactly where he'd thrown it earlier, impossibly unable to pull the trigger once he had it in his mouth. A fucking coward, that's what Castiel is. Can't save anyone, can't save himself, can't even kill himself. Of course, if the drugs don't do it for him, Lucifer will, so at least there's that to look forward to.
His fingers brush against a cluster of tablets, and they stick to the blood oozing from his broken fingernails. Perfect.
An hour later, he's soaring right over the camp, the ache of his missing wings absent. His grace is back, it must be; after all this time, it's come back to him, and he can do anything, go anywhere. He's an angel of the Lord.
Thinking of Dean (always thinking of Dean, before all else), he feels a moment of bottomless fear, the high of his flight briefly overshadowed. He hasn't seen Dean in - he can't remember. He's sure Dean is fine, though, Dean is always fine. Castiel and Sam look after him; even if he doesn't want to be fine, he hasn't got much of a choice.
That sparks a memory, blindingly bright like the flash of Anael's grace as she perished by his hand. Sam said yes.
But they'll be okay. They'll make it out okay. Castiel is an angel of the Lord, he can fix anything and everything, even Sam. He can't fix himself.
The ground tries to swallow him with little success as he stumbles to the riverside, mud stealing the warmth from his bare feet. There's Dean's soul, a faint glow between the layers of mud. Buried.
"Dean, Dean, Dean," the water reaches his knees, "You don't want to dig yourself out again, Dean." Wings spread wide, he's falling down, down, down. Falling.
Silence meets his admonishment; maybe Dean doesn't want to talk, because he never does, these days. "I'm sorry, Dean," his grace is floating away from him, shimmering bubbles of God's perfection, "I didn't mean to. I didn't know you'd be trapped."
Tiny shudders wrack his body as the cold invades, and he can't for the life of him figure out why. He shouldn't be able to feel anything. Must be the vessel, he thinks, even as the cold is joined by a guilt that fills his bones to overflowing. "Can you fly, Dean? Will you fly with me?" He sees Dean's wings, but he likes asking stupid questions - Dean usually answers them. And even if he doesn't get a reply, he's made Dean smile like he hasn't in two years, two long fucking years of sex, drugs, and Hell on Earth.
"Don't leave me, Dean. Don't you fucking leave me."
Water laps placidly at the riverbank, wiping away only the one set of footprints. "I never did, you stupid son of a bitch."