At first Dean isn't sure what woke him.
He's in Cas's cabin. They spent the evening drinking, and talking about things, and avoiding talking about Sam, or angels, or the fact that the government has gone sufficiently to shit that finding an abandoned summer camp and making it into a home base is actually a viable course of action. Cas fell asleep first; even now, with most of his angel mojo gone, he's got a better alcohol tolerance than Dean, but he also started drinking before Dean showed up.
Dean had been getting his things quietly together when Cas started twitching and moaning in the grip of a nightmare. Not that Cas having a nightmare was any kind of rare event, but this one seemed worse than usual, complete with muttered words in what Dean figured was Enochian, because it sure wasn't English. Dean had hesitated, then set his jacket back down and slipped onto Cas's narrow bed and pulled the former angel against his side, the way he'd done for Sam in those first horrible weeks after Jessica died. And by the time Cas had drifted into real sleep, Dean's eyes were heavy and he'd closed them for just a second.
But now he's awake again, and thrumming with tension, because the sound that woke him is registering and it's one he was hoping never to hear again. There have been few times in his life that the fluttering of wings didn't mean someone was about to screw him over; if there's an angel in the room, that just can't be any kind of good.
He blinks the sleep away and focuses; Cas's kerosene lantern is burning low, and all Dean can make out is a tall shape in the corner. For a moment he thinks Sam but it's not quite tall enough, and too slender through the shoulders. Just...wishful thinking.
"Who the hell are you?" he snaps, and struggles away from Cas's weight. Cas makes a small protesting noise but Dean knows he can't expect help from that quarter anytime soon; Cas is still pretty new to this sleeping thing and waking doesn't come easy or fast to him.
"Relax, Winchester," the shape says, tenor and British. "I'm just here to talk to Castiel." Dean's guts turn to ice and he looks longingly at his jacket, which contains all his serious weapons and is closer to the shape than it is to Dean. In the meantime he can at least put himself between Cas and the intruder, so he does that, takes a step away from the bed. Behind him, Cas seems to be making stabs at consciousness.
The shape speaks again, and this time it's softer, almost tender. "Oh, Cas," it says. "What's happened to you?"
"You dicks threw him out, remember?" Dean says, rougher than he means to. He's been watching Cas lose his nature for years now, and it's heartbreaking. Which is kind of a chick thing to think, but hey, Cas can't read his mind anymore, so no one has to know.
Cas suddenly sits up straight. His voice is thick with sleep and alcohol, and he sounds utterly disbelieving when he says, "Balthazar?"
Just like that, with that damned angel speed, the tall shape is gone, behind Dean and bending over Cas; Dean spins, but the angel twitches a hand at him and he's shoved back a bit; not really restrained, but he can't get any closer either. Another twitch and the lantern gets brighter, and finally Dean can see their visitor clearly.
He's blondish, good-looking in a horsey English kind of way, and dressed in dark slacks and a jacket and a grey t-shirt with a v-neck so deep Dean can practically see his navel. And Cas is looking at him like he's seen a ghost. Which in a way he has; they haven't seen any of the angels in over a year.
"Balthazar," he says again, more clearly.
"Castiel," Balthazar says, and Dean watches Cas wince at the name; Balthazar sees it too. He puts one hand on Cas's arm and says, urgently, "You have to come with me."
"What?" Cas says, and Dean echoes it. Balthazar turns to fix him with a glare. "Shut up," he says savagely. "It's your fault he's like this in the first place, so you keep your mouth shut." He turns back to Cas, eyes him for a moment, and touches his fingers to Cas's forehead—that's a motion Dean knows and he tenses, but Cas and Balthazar stay where they are; suddenly Cas looks clearer, and Dean realizes that Balthazar cleaned the booze from his system. The ability to heal others was one of the last things Cas lost, and people still do better if he tends them.
"We're leaving," Balthazar says then, and Cas's eyes widen. "All of us, Castiel, and you have to come now, this is the last train. I don't have much time."
"Who's 'we'?" Dean asks; this time Balthazar doesn't bother looking at him, and his lips twitch in annoyance, but he replies nonetheless. "The Host. The angels. We're leaving."
Cas laughs suddenly, a jagged sound with no humor in it. "I'm not an angel anymore, Balthazar," he says, sounding so much like his old self that Dean actually jumps a bit. Though he's hard-put to imagine Cas looking less like the holy tax accountant. For one thing, the trenchcoat is long gone, ripped into bandages for a man who bled out anyway back when they still thought they could get ahead of the Croatoan outbreak. At the moment Cas is wearing cut-off sweatpants and a t-shirt that used to be Dean's.
"You can be," Balthazar says, low and urgent. "Come with me, come with us. The Host is leaving. The Morningstar has taken his vessel, Castiel. This is the end."
The Morningstar has taken his vessel, that can't...Sam didn't...Sam wouldn't...and Dean is trying to work out what else it could mean when Balthazar turns to look at him again, and there's still anger in his eyes but there is pity too.
"Yes, Winchester. Your brother accepted Lucifer. It was a few hours ago." Balthazar says it with the blunt air of someone who thinks there's no point in drawing out the agony.
"I dreamed it," Cas says in sudden understanding, and Dean looks at him, knowing that the expression on his face is begging Cas to say it's not true, that Sam hasn't given in, but Cas looks back with such sadness that Dean has to close his eyes against it, and he can feel the tears starting to prick. That's when Dean's legs give out. One hand runs through his hair without conscious direction, but he needs the other to hold himself up.
"Cas, we don't have time. We have to go right now or we'll be too late," Balthazar says.
Cas looks at him, and his eyes are full of longing, but he shakes his head. "They won't take me back."
"They will," Balthazar insists. "I have permission to be here, Cas. They won't leave you to die while Lucifer walks the Earth in his true vessel." He laughs, short and bitter, and says, "Zachariah told me to tell you it's an order. Come with me, Cas. Please."
Dean is only barely staying upright, and he can't seem to catch his breath, but when Cas looks at him he nods. Gathers himself and manages, "Cas, go," before his voice breaks. Balthazar spares him a glance that looks almost like respect.
And Cas looks at him for a long moment, and Dean thinks distantly that this is what dying feels like—not the pain of whatever injuries killed you, but dying itself. Cas is going to go, and at least he'll be happy, and Dean knows he won't last long without Cas, without Sam, but that's all right.
Cas turns back to Balthazar and there's a long pause, and before Cas even speaks Balthazar is beginning to shake his head. "I can't," Cas says. He sounds like he's trying to be gentle, trying to break the news of his own damnation gently. "I chose this a long time ago." His gesture takes in the room, and his own body, and Dean, who is still trying to remember how to breathe.
Balthazar says helplessly, "Castiel." Cas meets his eyes and shakes his head and says again, "I can't." Balthazar's voice is toneless when he says, "I can't come again," and Cas replies, "I know. But thank you for trying."
Balthazar's face is a mask as he leans forward and kisses Cas on the forehead. He straightens, and stands, and to Dean's eyes he moves as if he's in pain. "Castiel," he says once more, and then he's gone.
Cas stares at the spot where Balthazar stood for long enough that Dean manages to get his breath back, for now at least. He clambers to his feet, feeling like he's been hit by a truck, and makes it to the bed to sit next to Cas.
"Why didn't you go?" he asks straight out; Dean's never been good at subtlety, that was always Sam's job, and right now is not a time he can play against his strengths. Cas looks at him like he's an idiot and says, "I chose this when I chose you." Dean shakes his head, because that's not an answer, but Cas clearly thinks it is. And Dean doesn't know what else to do, so he reaches out and puts his hand on the back of Cas's neck and pulls him forward and kisses him, gently at first but harder as Cas returns the pressure.
It's dawn when Dean pulls on his clothes and walks out of Cas's cabin and looks up at the sky and says, "Michael. Yes." And there is no reply.