"Lilith was the final seal. I killed her, and I set Lucifer free."
"Yeah. You chose a demon over your own brother—and look what happened."
"I would give anything—anything—to take it all back."
"I know you would, Sammy. And I know how sorry you are. But I just don't know if I can trust you."
"Maybe it's best we just go our separate ways."
"I think you're right."
"You know who I am."
"Thanks to you, I walk the earth. Now, I want to give you a gift."
"Go back to hell. I don't want anything from you."
"That's not how this works. You're the one, Sam. You're my vessel."
"No. No. That'll never happen."
"I'm sorry, but it will. I will find you. And when I do, you will let me in. I'm sure of it."
Sam stands frozen, staring at the empty place where Lucifer's apparition had vanished for what feels like eternity. When the paralysis finally breaks, he moves fast, diving for his phone.
He paces the floor as it rings, unable to stand still - then yanks the phone away from his ear as Dean's voice snarls,
"Damn it, Cas, I need to sleep!"
"Dean, it's me," Sam says, quietly. "Not Cas."
"Sam?" Half a beat. "You got any friggin' clue what time it is?"
"Um, it's--" He looks around for a clock.
"Quarter past four," Dean supplies. He sighs. "So why are you calling?"
Sam's hand tightens on the phone.
"I'm-- it's important."
Succinctly, Sam explains what happened, all of it. When he's finished, there's a short silence.
"So you're his vessel? Lucifer's wearin' you to the prom?"
"That's what he said," Sam tells him. He's not aware of the bleakness in his eyes, the faint hope in his voice.
"Just when you said you were out, too. Guess you're gonna get sucked right back in, huh, Sammy?"
Disbelief paints his words. "That's it? That's all you've got to say?"
"I guess I'm a little numb to earth-shattering revelations at this point," Dean informs him.
Sam scrubs his free hand over his face. "So what are we gonna do about it?"
"What, you're just gonna walk back in and we're gonna be the dynamic duo again?"
He feels the impact of Dean's words as though he's just taken a hard right to the jaw.
"Dean, it doesn't have to be like--"
"Look, Sam, it doesn't matter what we do. We're the, uh, the fire and the oil of the Armageddon. You know what, we should just pick a hemisphere. Stay away from each other for good. We got a better chance of dodging Lucifer and Michael and this whole damn thing, if we just go our own ways. Stay separate. You hearin' me? Stay away."
"No, Dean-- don't, listen to me, don't do this, we can--"
The silence when the call disconnects is somehow worse than anything he's ever heard. Then again, it's nothing more than he deserves.
Three days later, his phone rings. Dean gets right to the point, giving him a location and a time to meet.
His brother's already waiting at the bridge when Sam arrives.
"Here." Dean pulls out Ruby's knife as Sam approaches, and Sam can feel his own jaw drop and his eyes widen as his brother holds it out to him, handle first.
"If you're serious and you want back in...you should hang on to this. I'm sure you're rusty."
Sam takes it. It's easier to look at the blade than to meet Dean's eyes.
"Look, man, I'm sorry. I don't know. I'm...whatever I need to be, I guess," Dean says. "Point is, I was wrong."
He does look up, at that, searching Dean's face. "What made you change your mind?"
"Long story." Dean sighs. "Maybe we are each other's weakness, I don't know. Maybe they'll find a way to use us against each other. They're sure gonna try. But the thing is -- we're all we've got. We keep each other human."
Sam swallows hard. "Thank you. Really, Dean. Thanks. I -- I won't let you down."
His brother nods. "I know you won't."