A/N: What's this? Another fic when she hasn't updated her others yet?
I suck, I know. But I just can't help it. Shh.
Know where the title is from? Marry me.

I don't own Supernatural. Dates are vague and may be inaccurate.

1.

15th of December, 2014

"Dean," Cas urges. "You've got to move. You've got to get up." He grabs desperately at the broken man as Dean nudges Sam, pulling at him uselessly. The white suit seems blinding, glaring at him, whispering I won, in the end. I did. I did. "Dean, you've got to move. We've gotta go."

"Go," Dean whispers. "Just go, Cas."

Cas gazes at the man as he clutches his brother. Dean has not been like this, not for many years – he has become cold, impossibly so. And Cas does not know, he really does not know, what to do anymore. Live or die. Give or take. Stay or go. If they stay, they'll die. If they go, they'll die sooner or later. What's the difference, really?

When your life is on the line, do you throw it away to save the people you love? Or do you run away, like a coward, to save yourself?

"Okay, Dean," Cas says, kneeling down beside the man and rubbing his back. He doesn't protest. "Okay. I'm here. It's okay."

2.

20th August, 2010

"He said yes," Castiel says stiffly. "He said yes."

Sam blinks. Bobby blinks. Time itself appears to simply freeze, useless and unimportant. Finally, Bobby speaks up. "What?"

"He said yes," Cas whispers, mostly to himself. "He said yes. He said yes." He shakes his head, looks up, and then turns infinitesimally. "Turn on the TV."

"What?"

"Turn on the TV."

When Bobby just stares, Sam moves over to the old battered couch and switches on the TV. Mass explosion, the news broadcaster is saying. Hundreds dead. Not as bad as could have been. Mysterious. Body of middle aged man found.

Lucifer. Lucifer, or what looks like bits of him, scattered across the muddy ground.

Body of young man, mid-thirties, also discovered recently.

Dean. Dean, almost untouched, looking impossibly peaceful.

"Michael took Lucifer by surprise, I'm guessing," Cas says quietly. "Short squabble, it seems. Didn't get far. Michael has always been the more powerful sibling. It seems almost too easy, doesn't it?" And then, like a man losing in friend in the middle of combat and not entirely knowing how it happened, he breaks down and cries. Not proper crying, of course, because he cannot – but sobs, great, wracking, sobs that make him feel so, so tired – the sort of bone-deep tired that only ever worsens with time.

3.

24th November, 2013

"Dean!"

Behind you, Dean. Behind you. There's a demon with a very, very sharp knife, and it's about to lop your stupid head off.

"Shit." Dean's swerving out of the way. Cas is watching him, not paying attention his surroundings. Then a demon, spinning him around, ready to skewer him on its pretty little knife, one that will kill Cas, will kill him because he's human and so, so vulnerable.

"Cas!" Yelling. Dean's voice breaks. Footsteps towards him. But no pain. There's no pain.

"Dean?" Cas's eyes flutter open. "Dean? You okay?"

He looks down, and lets out a cry that doesn't sound human.

At his feet lies Dean, a blade through his gut, his own blade through a demon's. Blood coats him, and his body is broken, broken and twisted, but his face is so peaceful, and God, Castiel can't take this, not now, not now-

"No. Dean. Fuck." Cas grips at the man, not caring, not caring about anything, and cries until his eyes hurt and his chest begs for air and his companions urge him to come, come, they need to leave, come. "Dean," he whispers, like a prayer.

But it's useless, Cas knows.

It's way too late for prayers.

4.

5th April, 2051

"Dean."

The man looks up, and smiles warmly. His whole face warms up when he smiles, lights up in a way that Castiel has become accustomed to. He nods to Tessa, clambering to his feet. "That time already, eh?" he asks, with a soft, comfortable chuckle.

Castiel moves back into the shadows, not letting the human see him.

Tessa laughs. "I think it's well overdue for you, Winchester," she says affectionately, and holds out a hand. "There. Seventy-two? Isn't that some sort of hunter record breaker?"

Dean grins. "And yet, Sam always has to get one up on me."

"He will join you soon, I'm sure," Tessa placates.

Dean shakes his head. "Let him have all the time he can," he says firmly. "The kid needs it." Sam is almost seventy, and Dean still calls him a kid. Castiel shakes his head with a smile. He will never understand humans.

"Better go then," Dean says, smiling as he takes Tessa's hand. "Onto the next adventure."

"That is the – what is it you humans say? – cheesiest line I have ever heard you use, Dean," Castiel jokes, emerging from his hiding place.

Dean's eyes light up when they rest on him, and the man cocks his head to the side, old, worn face brightening pleasantly.

"Coming, Cas?"

Castiel smiles and steps forward. "Wouldn't miss it for the world."