"Did you know," Dean repeats.

Cas stares, his eyes cold and dark, and so, so angry. "I have told you I did not," he says sharply. His lips draw together in a tight line as he regards the man he's loved unquestioningly, unconditionally, since he first laid a celestial hand on him, and the betrayal that settles in to Cas's fair features punches at Dean hard. "You believe that I am lying?"

There's a moment when Dean says nothing, and the temperature in the room seems to drop ten degrees.

"I see."

"Cas-"

"I hunt every case with you. I lie in your bed, I make love to you, I am committed to you in every way. And still you do not trust me. You doubt my loyalties as though we have just met."

And Dean knows he should stop. The whisper in the back of his mind reminds him of ten million reasons and ways that Cas has proven himself to be completely and unflinchingly on their side, but Dean's never had a very active mouth filter so his retort rises effortlessly to his lips. "Yeah well, pardon me, but you loyaltie do seem to get called into question a lot more often than the average Joe's."

Cas exhales, sharp and low, a habit he could have picked up from either Winchester, and for just a moment Dean half-expects the angel to fly at him in a rage, throw him up against the wall the way he did so long ago. This motel room doesn't seem large enough to contain the utter fury radiating from Castiel and there is not an flicker of Sam's sad puppy eyes swimming in the pools of blue. "I am leaving," Cas says, his voice blank and a little reminiscent of the day he returned from Heaven's Bible Camp. It was the very first time he'd given up on Dean, accepted that their alliance was in direct conflict with his orders, and hearing it now freezes Dean to his core. And he wonders - he wonders - if maybe he is wrong about this whole thing.

Cas's eyes move to him once more. He isn't sure if Cas is reading his mind, as he's been apt to do on occasion, and can hear Dean's doubts floating around in there, or if he's having doubts of his own. But he doesn't fly away or disappear. He waits, his head tilted to the side in a way that shatters Dean's heart.

"So, go," Dean snaps, turning away so he doesn't have to watch as their relationship breaks in two. It's hard to believe that just three days ago he was telling his brother Don't be mad, Sammy, but there might come a day when Cas and I are ready to get out of this business. Lead a more quiet life, you know. Still hunt, just not all the time. And Sam had smiled, so bright and happy, like Dean had just confided his intention to propose, and if Dean had returned it, beaming a little himself, well. It doesn't matter now.

"Fine," Cas whispers, a touch of sadness lacing his voice, chasing away the anger. "I will return when-"

"Don't." Dean swallows thickly. "Don't return at all. Sam and I can handle whatever demons or monsters or witches that cross our paths. We were doing fine before we met you, and, honestly, double-crossing angels are a little more trouble than they're worth."

He's not sure what he expects. Maybe more arguments of his innocence, maybe stunned silence. But then Cas is all in his personal space, body heat pulsing against Dean's own, and he leans up to brush his lips to Dean's, soft, gentle, loving. It's a goodbye, as clearly as if Cas is saying the word, and Dean can't help returning the kiss, knowing it's their last. He's always been a little powerless when it comes to Castiel.

When he opens his eyes, the angel is gone.

The moment Sam enters their motel room, Dean knows something is very wrong.

His little brother has always had a decent poker face. He likes to tease him about it - big brother's prerogative and all - but the truth is that if it was half as bad as Dean is always claiming, Sam wouldn't be the excellent hunter that he is, and wouldn't have been able to pull the wool over Dean's eyes during his secret meet-ups with Ruby, when the demon was still a part of their entourage. So the fact that his face is pale, his eyes bright with worry, sends a dart of fear straight to Dean's gut. "Sam, what is it," he demands.

Sam looks over at him, placing the six-pack that he'd gone to the store for on the table. "While I was out, Garth called," he begins carefully. Somehow his soothing tone sets Dean even more on edge. "He said . . . that, uh, someone's been killing-" He pauses, and Dean knows what he's going to say, because there's only one species that would make Sam react like this.

"Angels."

Sam nods.

Dean's blood runs cold. "Anyone we know," he asks, trying to keep his voice from shaking, and failing magnificently.

"Garth wasn't sure," Sam answers quietly. "The hunter that told him about it, you know, he hasn't met . . ." He almost seems afraid to say the name out loud, and though it's been months since Dean has seen his ex, he can't find the strength to say it either. Both brothers leave the sentence hanging in the air. "The last one was a few hundred miles away, and there are a couple of hunters closer than us, but he thought we might want the job. Considering."

Immediately Dean begins throwing his clothes into his duffle, and he tosses Sam's bag in his general direction. "Get packing, Sammy. We're on the road in ten."

The drive to Charlotte, North Carolina seems endless, and with each passing minute, Dean can feel himself teetering closer and closer to panic. Ever since Cas disappeared this is the fear that has kept him up at night, the certainty that if something were to happen to Cas, if he were to get killed at the hands of another angel, or demon, or hunter, even, that Dean wouldn't be there or, worse still, that he wouldn't even know. And he knows without a doubt that their relationship is over, he's gotten that message loud and clear, but it doesn't mean that the idea of Cas lying lifeless on a street somewhere doesn't terrify him beyond all reason.

As the Welcome to Charlotte sign comes into view, he feels Sam turn concerned eyes on him. "Dean, we don't even know anything yet," he says gently. "I'm sure Cas is fine."

"Yeah," is all Dean can muster. He follows the signs to the hospital, relieved when Sam falls silent, and by the time they finally pull into the parking deck at Carolina's Medical Center, Dean feels like he could explode any moment. He parks the Impala in the first available space, and it takes every once of his self control to keep from full-o runnin to the entrance. Nevertheless, if he's walking a little faster than normal, Sam pretends not to notice.

The hospital is a flurry of activity when they pass through the entrance. The latest angel was discovered in the lobby, and while a quick look around tells both Winchesters that they have since carted the body away, authorities continue to mill around, taking pictures of the black wings, scorched into the floor. (Dean feels revulsion rise in this throat. Don't be Cas. Please don't be Cas.)

A police officer, older, balding, stops them as they get close. "Sorry, fellas, this is a crime scene."

Sam and Dean both flash their F.B.I badges. "Alonzo Mosely, F.B.I.," Dean says. He gestures to Sam. "My partner, Eddie Moscone."

"Martin Crane," introduces the officer. He sighs and steps back so Sam and Dean can get a closer look at the marks on the floor. "Gotta say, this whole thing is a mystery."

Dean stoops, and brushes his fingertips along the remnants of the angel wings. His throat closes up fearfully, so he's glad when Sam takes point.

"You guys have any theories?"

"Not a one. The hospital surveillance went apeshit at some point, so there's no footage of when the guy was killed, and no witnesses are coming forward. Kinda weird. Big place like this, you would think someone would have seen something, but all the employees on this floor say the same thing. There was no one there, and then a second later there was a dead guy on floor, surrounded by black wings. Fucking weird."

Sam clears his throat. "What did the guy look like?"

"Well, we assume he was killed by the stab wound to his heart, but we won't know for sure until-"

"No, I mean, what did he look like? Was he-" Sam glances down at Dean, who stands slowly. "Tall? Short? Light hair? Dark?"

Officer Crane raises his eyebrows. "Young guy, mid-thirties, probably."

Dean stops breathing.

"Medium height, blond."

Blond. And Dean can breathe again. At least he knows that the scorch marks at his feet don't belong to Cas, though he won't really feel better until he's checked out the other two cases Garth told them about on their way here. He's tempted to leave right now, truth be told.

"Let me ask you boys," Crane says, "it customary to send three F.B.I agents for one murder? Kinda overkill, don't you think?"

"Three," Sam and Dean repeat together.

"Right." Crane gives a small chuckle. "Though that other guy is little weird. Can't really blame them for sending in two more for backup. Probably just didn't want to miss anything?"

Dean's been doing this a long time, and he has learned to trust his instincts, rely on them when he can't be sure of what his mind his telling him. And right now, his instincts are sending off alarms inside his head so loud that he can barely think. He turns to Sam, trying to read his expression, trying to see if it reflects Dean's suspicion. Hope is starting to bubble beneath his skin, and hope is such a dangerous thing in this business.

But Sam is looking pretty interested too. "When you say weird . . ."

Crane grins. "Maybe you should just meet him," he says, and he takes a couple of steps forward, and it's only then, as they're drawing close, that Dean catches sight of the long trenchcoat, and the dark-haired man wearing it. The man's back is turned, he's talking to another cop, but Dean's heart starts sputtering out of control because he knows that trenchcoat, better than he knows his own skin. He's slipped it off Castiel's shoulders enough times to have memorized every inch of it - every crease, every fold.

"Agent Lennon," says Crane, and the man turns, and suddenly Dean is looking into the bluest eyes that have ever existed, eyes he hasn't seen in almost a half of a year,

And Sam's the one that says it because Dean can't speak, and he's not sure how long it will be until he finds his voice. "Cas?"