"Help I have done it again.
I have been here many times before.
Hurt myself again today.
And the worst part is there's no one else to blame."
-Breathe Me, Sia
Dean's heart burns, burns hot until it blisters and scabs and burns hotter still. How it always comes to this he has no real idea. Everytime they pull each other out of the ashes enough for a chance at happiness, it all collapses again. Like building a house slowly, beam by beam, and then watching the wood splinter and crackle, eaten up by red and orange flames.
He paces Bobby's floor, hearing the creaks in all the familiar places. Groaning planks thinning in age. And Cas isn't here to tell him to sit on the lumpy couch and just breathe for a while. Let the dusty air do its calming work instead of pacing canyons into the wooden flooring.
The moon shines through the windows, tossing odd shadows across the room through wards and sigils painted in with blood and tears and whisky. Not that any number of criss-crossing lines would keep Cas out now. Not while he strides oceans and traces continents as their new God.
Dean's face falls into his hands as the agony pulses through his veins again like being stabbed slowly, over hours at a time. Icy blade sinking into flesh, cutting out everything that matters until copper blood and never ending blackness remain.
A crash shakes him slightly, sounding like someone has thrown a rock through plate glass. Maybe Bobby or Sam. He doesn't want them to see him like this - nothing but a fraying knot and empty bottles. He is supposed to be strong, the unbreakable one that holds them all together fast, but caring has made him weak. What would his father say if he could see him now? This line of thought is interrupted.
"Dean," a voice says, shooting sparkling electricity down Dean's arms in a bursting flare. He turns slowly, the world creaking to a stop around him.
"Cas," he breathes when he does finish turning and his eyes confirm what he refused to believe his ears were telling him. The angel stands slumped over, practically falling down. His hair is flecked with broken glass and maroon blood. Even tendrils of black ichor trail down in lines across the strong bones of his face.
"I…" Cas pauses, looking like a lost child. "I need your help." Dean's knees feel weak. Everything about this Cas feels authentic. Every muscle shift, eye twitch, word. Every sign screams out that this is the man Dean loves. But how can he believe it now? How can he, when the person who stands in front of him also burned cities to the ground, slaughtered thousands upon thousands of innocents, and left nothing but the god-fearing masses in his wake? His breath must smell like blood. But Dean wants so strongly to trust in what he feels.
"I am sorry," Cas says. He nearly stumbles again. His eyes plead. "What I have done is beyond the forgiveness of any creature. And my betrayal to you. It is. It is unthinkable. I don't ask your forgiveness when I know I have no right to it. But I need your help before my actions, my foolish, selfish actions, lead to even greater ruin than they have already wrought." He cries out suddenly, hands going to his stomach. Blood spills from his hairline and the buds of his fingernails and blackness oozes from the corners of his eyes. Dean takes a step forward, then stops himself.
"How can I even know who you are anymore, Cas? A vengeful angel? An even more vengeful God?" Cas looks up to him, the blood vessels in his eyes bursting to a spackling of red.
"I am a creature of penance," he says. "And I refuse to cause any more death." The trenchcoat he wears is ripped and covered in innumerable stains. He has not given care to his looks in a very long time. This is not the immaculate God that once threatened him. But it is the way he phrases what he says, something about the look in his eyes, and Dean sees him. The angel in a trenchcoat he fell for, and who fell for him in every conceivable way, made of lightning and ocean spray.
Dean crosses the rest of the floor, hesitates for only a moment, then reaches his hands out to grasp both of Cas's shoulders, holding him up. Cas closes his eyes, basking in the touch. He looks like he could give in at any moment, now that he has felt Dean's hands supporting him one last time.
Dean takes in Cas's condition from a closer range. There is no way to deny the angel won't survive. He is coming apart at his very seams. His skin is melting away as he stands. It hurts to see, hurts deep in Dean's gut. He pushes down the urge to vomit at the sight.
"You dumb bastard," he says in a whisper. He uses one hand to reach up and cup Cas's cheek, rubbing his skin with a wandering thumb. "When we get you back to yourself, I'm going to kick your fucking ass." Cas doesn't correct him, though they both know Dean will never get the chance. If Dean thought these were anything but his final moments, they both know Dean would be throwing punches until his knuckles bled and his bones ripped through his skin.
"Thank you," Cas says, opening his eyes to look down at Dean. Cas absorbs the face in front of him like a sponge, soaking in every inch in his mind so he won't forget a single freckle. As if forgetting was every a possibility.
"Thank you for coming back," Dean says. Rain explodes on rooftops, and stars burst, and waves crash, and Dean holds Cas in his arms while he still can. Light shines all around them through the dark night, and actions say what neither man can bring himself to put into words. Goodbye.