Castiel is somewhere in Indiana when Dean appears on the side of the road.

It's so sudden, their eyes locking for barely a moment before Castiel passes him by. He curses, cranking down the radio and pulling over.

Dean hasn't moved, still facing south, hands in his pockets, shoulders slumped. Castiel approaches him, separated only by twenty feet of dust and asphalt. Dean says nothing until Castiel is by his side, and then only, "Hey, Cas."

"Hello, Dean." He tries to follow Dean's gaze but see only cornfields and a late summer sky. "What's wrong?"

Dean looks over at him, then, eyes crinkling up with the start of a smile. "Nothing's wrong."

"Is it one of the seals? I can call Sam; he's in Iowa right now but we can find him if-"

"No, Cas, relax. Nothing's wrong."

"Then why are you here?"

Dean shifts, turning his body to face Castiel. He looks the same as he always does – the same leather jacket, the same boots, the same weathered smile. "I just came to-" He sighs, then, stuffing his hands back in his pockets. "Never mind. You've got somewhere to be, I bet. I shouldn't have come."

He turns to go, and Castiel knows he has about half a second before Dean is gone with the breeze. He darts his hand out, latching on to Dean's shoulder.

"Stop it. Don't go flying away again. You came here for a reason."

"No, really. I just-" Dean sighs and curses. Castiel flinches. He'll never be used to an angel blaspheming. "I just wanted to see you, okay?"

Castiel lets his hand drop. "Oh. I see."

"I don't know, it was stupid. Just, with all this Apocalypse drama going on, headquarters are kind of crazy right now. Everyone's freaking out, and a lot of them are getting angry at me, and… I thought I'd try and get away from it, at least for a little while. Being with you – and Sam – always makes me feel… I don't know, calm. It's stupid."

"It's not stupid. Stay." Castiel pauses, turns towards the Impala. "I have some beers in the trunk, if you'd like. I know how partial you are to alcohol."

Dean grins and follows him back to the car. Castiel has never understood Dean's fondness for human food; it's not as if he has need of it. But Dean is more human than any of the other angels. He is the only one who seems comfortable in his vessel. The others wear their vessels like ill-fitting suits, but Dean is different. Castiel cannot picture him with any other face but this one. The eyes, the smile, the way he holds himself, are all so distinctly Dean.

They sit on the hood together, nursing their beers. For a long time silence lies between them. Castiel has never been good with his words, and Dean doesn't seem to need conversation. Sometimes Castiel forgets that Dean was an angel for thousands of years before they met. Dean is not used to having friends. The silence is always comfortable between them.

There is something unspoken, something ineffable, about their relationship. Castiel has a strong bond with his brother, an ease that comes from years in each other's company. With Dean, it feels different. Dean knows Castiel, built him from his core. Dean has cradled Castiel's soul in his hands.

"How are you?" Castiel ventures.

Dean shrugs a shoulder but says nothing. He doesn't understand human customs like opening up, like discussing feelings. Maybe he doesn't even know what feelings are. Though he'll answer any of Castiel's questions, he never volunteers details. He sets up walls when others come too close.

"Dean. You sought my company for a reason."

Dean looks at him for a moment, eyes softening, then tilts his head up to look at the sky. Already dusk is falling, the sky fading to a pale yellow, almost gray. "You remember when we first met?"

"And I shot you, then stabbed you?"

"Yeah. You seemed so surprised when I told you I was an angel. Why was that?"

Castiel leans away, taken aback by the question. "You weren't what I expected. All the other angels I've met are so serious. So militaristic. You are different. You seem more… comfortable on Earth. With me. With humans."

"Yeah," Dean sighs. Castiel waits for him to continue, but of course he says nothing.

"Why do you ask?" he says finally.

Dean frowns and rolls the bottleneck between his hands. "I've been thinking recently."

"About?" This is like pulling teeth. Castiel has never had an easy time discussing his innermost thoughts with Sam, but at least it's not like this.

Dean waits for a moment, as if weighing the words on his tongue. "In Heaven, for the last few millennia, no one really paid attention to Earth. Lucifer was on lockdown, demonic activity was at an all-time low… But I couldn't look away. I kept going to the edge of Heaven, watching humanity. I guess I got a little addicted. The other angels thought I was crazy; they couldn't understand why I was so fascinated by your kind."

Castiel has heard this before. Anna said something similar, in explanation for why she fell. He wonders where this is going.

"That's why I'm so… y'know, human. I spent a long time studying you guys. You all have similar speech patterns, hand gestures. It wasn't that hard to figure out. And sure, the vernacular changed over time, but I learn quickly. So when I had to assume a human vessel, it felt… I don't know. Right. It felt comfortable. Like I belonged in this form."

"You do," Castiel says. "This body is yours."

"Well, it was some poor shmuck's before I took over. I still feel bad about that sometimes. But, you know, he was made for me. Like, he was born with the sole purpose of being my vessel. So I try not to lose sleep over it."

"You don't sleep."

Dean laughs softly. "Yeah. Sorry. Like I said, just using the vernacular. It's just… Now, when I go back home, when I break out of this body and stretch my wings, it feels different. It doesn't feel like home anymore. Even with all my grace crowded into this one tiny human form, I'm happier."

"Is there something wrong with that?"

"I don't know. Maybe. In Heaven now, I've started adopting this form. I like it."

"I like it too," Castiel murmurs, before his brain catches up with his mouth. For a moment their eyes meet and Dean turns pink. Apparently he's become so used to the vessel he no longer has control over its bodily systems either.

"Anyway." Dean clears his throat, ducking his head. "I don't know what I'm trying to say."

"It's all right, Dean. I think I understand."

Dean pauses, opens his mouth to say something, and stops. As if he's not sure he can choke out the words. Finally, he says, "When I-" And stops again.

"What is it?"

"When I pulled you from Hell. You know we started fighting our way to you the moment Lilith sicced her dogs on you, right?"

"I didn't know that. It's comforting to hear."

"I dove right into Hell. Fought my way through legions of demons to find you, alongside my entire garrison. Alongside hundreds of garrisons."

Castiel inhales sharply. He forgets, sometimes, how many angels sacrificed their lives to save his soul. It seems so disproportionate. He didn't deserve to be saved. Dean may say otherwise, but it's true. Even the Righteous Man is not worth such a cost.

Then, a thought occurs to him that makes his blood run cold. "Wait. Time worked the same for you as it did for me, then? In Hell?"

Dean's face falls. "Yeah."

No. No, that's not right. Castiel feels his breaths shorten, his chest constrict. Forty years. Dean spent forty years in Hell, looking for him. All this time, he's been moping over his own suffering, and he never even considered Dean's sacrifices. Never considered that Dean had been through the same thing. "Dean. You never told me."

"It wasn't a big deal. I kicked most of their asses anyway."

"Forty years, Dean."

Dean shrugs a shoulder, but the motion is rehearsed. "It doesn't matter."

"Of course it matters. You suffered."

"I'd do it again. A thousand times again. Cas, you're worth it."

"Stop saying that."

"Then stop denying it!" Dean turns to face him, and his immediately becomes worried. "Cas? What's going on? Are you okay?"

Castiel realizes then that he's hyperventilating. He wants to say, "I'm fine, Dean," but his mouth isn't working, it feels dry, and his heart is pulsing faster and faster and he can't breathe. All he can see are the fires of Hell and Alistair with his knife and oh God oh God he's back on the rack-

"Cas! Snap out of it!" Dean's hands are on his wrists, his eyes wide with concern. "What's going on?"

Castiel focuses on the feel of Dean's skin on his, the feel of Dean's breath on his face. He controls his breathing, pinches his eyes shut, and forces himself to calm.

"Are you okay?" Dean asks, loosening his grip on Castiel. Castiel wants to tell him no, keep holding on, otherwise I might break apart again, but instead he just nods.

"Another panic attack?" Dean has been with him before when the memories became overwhelming.

"I'm okay now," Castiel says, swallowing. "I'm sorry. Ever since… Talking about it is hard for me."

"We can change the subject."

"No, you had a point to make, go on. I just didn't realize… Dean, you spent forty years in Hell."

"So did you."

"It was different. You were there by choice."

"I was there under orders. I wasn't even supposed to rescue you."

"I- what?" Castiel stops, eyes finding Dean's. There is nothing but honesty there. "What are you talking about?"

Dean relaxes, leaning back out of Castiel's personal space. "Remember what I said, about being attached to humanity? Some of my brothers and sisters, well… Let's just say it didn't make me popular upstairs. I was never supposed to come near you, because I was considered unworthy."

"Dean, if anyone's unworthy, it's-"

"Shut up, Cas. Just hear me out."

Castiel's words fall short. He nods to Dean to continue.

"But I found you first," Dean says, "and I just couldn't wait for the others. Not while you were suffering, your soul darkening with each soul you put on the rack. I couldn't watch you in that much pain. Your soul, Cas. It's so pure. Like none I've ever seen. I couldn't let that continue."

"So you gripped me tight and raised me from perdition."

"I marked you. I made it clear to all my siblings that I had found you first, that I had saved you. And I think that's when I started falling."

Castiel blinks slowly, unsure he heard correctly. "Dean?"

"Yeah," Dean says, and he laughs humorlessly. "You heard me. I'm falling from Heaven."

"Why?"

Dean gives him a sidelong look, something intense and cryptic. Castiel has seen that look before, when Dean thinks he won't notice the staring. Castiel doesn't know what it means.

"You really don't get it, do you?" Dean asks.

"Dean," Castiel says, fear rising once more in his voice. "What's going on? What's wrong?"

"Nothing's wrong. I think… I think things might be going right, for the first time. That maybe this is fate. This is what's supposed to happen."

"You're supposed to fall?"

"I don't know. My father works in- well, I was gonna say mysterious ways, but that seems like a cliché. You know what I mean."

"Don't change the subject. Why are you falling, Dean?"

Dean wipes a hand down his face, curses, then drinks down the last of his beer. "It's because of what I told you. I don't know if I want to be an angel anymore."

Castiel waits, patiently, for Dean to continue. He knows how hard this must be to say.

"I feel like I belong here. With you. And Sam, and Bobby, and- I don't know. I wanted to be with humans for so long. And now I might be…" Dean drops his head, unable to finish. Castiel scoots closer, placing a comforting hand on his shoulder. He never knows how to comfort such a powerful, otherworldly being, but maybe that isn't such an issue. Maybe Dean is more human than he thought.

"You know, all those years, when I was watching humanity. There was one thing I wanted more than anything else." Dean runs his tongue over his teeth, as if weighing the words on his lips. "I wanted to fall in love."

Castiel stills as the word, but says nothing.

"It's cheesy, I know. Straight out of some dumb Meg Ryan movie. But angels, we don't really… We're mostly formless, while in Heaven. Beings of celestial intent and all. Love doesn't exist, emotions don't really exist. But when I saw you humans… Jesus. This sounds stupid when I say it out loud."

"It doesn't, Dean."

"Whatever. I just wanted to be human, I guess, to feel things. Maybe falling isn't so bad."

"But why now? Why was pulling me from Hell the catalyst?"

Dean's smile is bitter with irony. "Come on, dude. Surely you're smart enough to figure that out."

And then, oh, then Castiel understands. Maybe this thing that's been weighing down his chest, this ineffable emotion, isn't one-sided.

His hands and lips work before his brain catches up, and then Castiel is leaning in and kissing Dean. They crash together as if this is urgent, as if they have been waiting thousands of years for this. And then Castiel realizes, maybe Dean has been. It is almost as if Dean was anticipating Castiel's reaction, the way he answers so immediately to Castiel's lips on his. Dean pulls him in closer, one hand reaching behind Castiel's head. It is good, it is great, it is everything Castiel has wanted for all these months but never thought he'd receive.

Almost as suddenly Dean pushes him away, twists his body away from Castiel and hunches in on himself.

"Dean?" Castiel asks, surprised by the sudden mood shift. He reaches out for Dean, a hand on the sleeve of the leather jacket, but Dean brushes him off. The panic rises, threatening to take over once more. Dean doesn't want this. Dean doesn't want him. Castiel was wrong. "You're not-"

"Stop," Dean commands, the word sharp and angry. Sometimes Castiel forgets how truly terrifying Dean is when he tries to be. Dean is a warrior.

"I thought you wanted-"

"Of course I want you, Cas!" Dean exclaims. Castiel gets a glimpse of a profile, of angry eyes, and then Dean turns away again. "Who wouldn't want you?"

"I don't understand."

For a long moment Dean says nothing. Castiel is so open, so vulnerable, arms reaching for Dean. But Dean is strong and stoic and closed off right now. This is how their relationship is, sometimes. Castiel depends on Dean, begs for him to stay, and then Dean flies off without a goodbye.

"I don't-" Dean starts, and then stops. He takes a deep breath. "I'm falling because of you."

"I'm sorry," Castiel says, the words instinctive, spilling out before he can stop them.

"Don't-" Dean hisses. Then, finally, he turns, eyes locking onto Castiel's. "Don't ever apologize for this."

Castiel waits a beat. He will give Dean the time and space he needs to continue.

"I saw your soul in Hell," Dean begins. "Surrounded by all this blood and gore, violence and destruction, and yet you were the purest I had ever seen. Of course I fell in love with you. Who else would I-" He cuts himself off again, cursing. "Maybe it's some kind of sick fate. That I fall in love with the Righteous Man. I don't know. But now I'm falling, I'm becoming human, and I want it, God, I want it so badly it hurts. Sometimes it's so unbearable. I think of you and my grace just explodes with all these emotions angels aren't supposed to feel."

Castiel takes a hesitant breath, unsure if he can say something. Finally, he says, "You know I feel the same, right? I always have, Dean. I love you."

Dean laughs shakily, glances up at Castiel. He reaches out a hand, tentatively, and hooks a finger around Castiel's thumb. "I disobeyed Heaven to save you. And now, with everything, the Apocalypse, I'm beginning to have… doubts. I don't know if my superiors are doing the right thing. I don't know if I'm doing the right thing. But no matter what, I know… I know being with you feels right. You are the Righteous Man. And I belong at your side."

Castiel lets Dean play with his hands. Dean has always had a strange fascination with Castiel's hands, running his own fingers along the bone of Castiel's wrist. It occurs to Castiel only now that it's because they're Dean's own creations.

"I'm scared." It is a quiet confession, almost too quiet to be heard. As if Dean is scared even to say the words. "I'm scared of falling. I'll lose everything."

"Not everything," Castiel says. Dean flashes him a quick grateful smile.

They sit in silence for a moment, the weight of the conversation sinking in. Castiel tries to imagine what it would be like to be where Dean is now. Being an angel is Dean's whole identity, his whole life. He is defined by his role. What is he without it?

Castiel's friend. That's who he is.

Castiel leans in, pausing this time a few inches from Dean's lips. Asking permission. Dean closes the distance, soft and uncertain against Castiel's mouth. It is the most human he has ever been.