It was the best birthday he'd ever had.

In fairness, every birthday since the whole being-dead-and-in-hell experience was the best ever, but even so this one had been pretty sweet. The girl at the diner had made him a special birthday pie and delivered it personally. He'd made Sam wear one of those little cone birthday hats all day and gotten it on camera, giving him ideal blackmail material. And to top things off, he and Sam got to pound on what had to have been the world's dumbest shapeshifter. All in all, pretty good.

So when his phone rang and he saw Castiel's number on the screen he had to wonder what Heaven had cooked up to mess up his perfect day. "Please, don't ruin this for me."

"Where are you?"

The tone in Castiel's voice killed Dean's urge to tease him; he sounded so tired. "Everything okay?"

"I..." He sighed, and Dean wasn't sure he'd ever heard Castiel sigh like that before. "Where are you, Dean?"

"Milwaukee, Highlight Motel, room 3," Dean said, and with a faint flutter of wings Castiel appeared in the doorway. "Whoa. For future reference, Cas, you show up looking like that, the answer to 'Everything okay?' is no."

The entire left side of Castiel's face was marred by a livid purple bruise, his eye swollen shut; his coat was torn and filthy and his left arm cradled against his side in a way that screamed his ribs were in pieces. "It's healing."

"That's healing?"

"I waited to call until I thought it was presentable."

Dean raised his eyebrows. "Thanks for the mental images, Cas. Christ, what happened? You look like you got hit by a truck."

"That would have been preferable." He swayed slightly, his fingertips brushing the wall.

"You wanna lie down? Your face doesn't look like it can take any more damage."

"I think I will." He carefully picked his way around the party debris littering the room and Dean could see how hard he was concentrating to stay upright. "My head feels...I don't know how to describe it," he said, lowering himself to the bed. "Like I drank a dozen liquor stores." Once he was stretched out flat he glanced up at Dean. "Why do you have that on your head?"

Dean patted his cardboard hat. "It's my birthday."

Castiel's brows furrowed. "It don't understand the connection."

"It's...I don't know. Custom. You wear dumb hats, you eat cake, blow out candles, all that. It's just what humans do." It was kind of fascinating to watch the bruise heal; as he spoke it faded from purple to a sickly green and the swelling around his eye went down enough for it to slit open. Dean whistled through his teeth. "I gotta say, that looks like it hurts like a bitch."

"Is 'like a bitch' more or less than 'considerably'?"

Dean didn't know if he was actually trying to make a joke or was just beat up enough that he'd lost what little grasp he had on Dean's sense of humor. "Closer to...I don't know, a whole lot."

"Then yes. It does in fact hurt like a bitch."

Dean grinned; there was almost nothing better than getting Castiel to curse. "I want to take a look at your ribs, that okay?"

He nodded and Dean unbuttoned his shirt, careful not to jostle him too much. "Shit. Cas."

Dean didn't know how Castiel was breathing - or at the very least, how he wasn't screaming. Forget his face, his entire left side seemed like one large, dark, mottled bruise. The bruising wasn't really what had Dean concerned though; his rib cage was smashed and so caved in Dean could see the bones moving under his skin each time he breathed. Castiel jumped when Dean skated his fingers over his ribs. "Sorry, sorry," Dean murmured.

"It's all right."

Dean shook his head. "How're you even talking?" His torso was streaked with dried blood and Dean could see spots where the bones had jutted out through his skin. "Next time you get chewed up like this, don't wait to call me."

"I didn't know where you were. It would have -" Dean's fingers brushed over a particularly rough spot and Castiel let out a strangled groan. "It would have created a disturbance."

"I don't give a crap. You call me right away." He could feel the bones shifting and knitting back together under his fingers. "Man, that is just freaky."

"There's..." His voice was tight, his lips a thin line and his eyes fixed on the ceiling. "Further down. It''s very bad there."

Dean carefully worked his way down until he found the spot he meant; two ribs were splintered and jagged, their edges grinding together each time he breathed. "Hold your breath," he said, and it was a little...unsettling how quickly and completely Castiel's chest stopped moving. Dean shook it off and put hard pressure on the ribs, pressing the broken edges into place. Castiel's eyes went wide and his hand latched around Dean's arm; Dean stroked his thumb along his the line of his jaw, keeping rhythm with his pulse.

Dean watched the hotel clock, counting the seconds. Once two minutes passed he glanced down; this would be around when your average human would start having trouble, but Castiel only blinked at him, not showing any apparent distress. Time crawled by, another minute passed, then two; he felt seeing Cas go so long without breathing start to mess with his head and found himself counting his heartbeats. At five minutes he eased the pressure and the bones stayed in place. "Okay, breathe now. Easy, though, easy, not deep."

Castiel took an experimental, shallow breath and Dean saw relief flash across his face. "Oh. Oh, that's much better. Thank you."

"Yeah, it's awesome when all your bones are where they're supposed to be." He did another quick examination but that seemed to have been the worst of it. "What the hell did you lose to?"

"The sequence of events would take too long to get explain," he sighed. "It's taken care of now, anyway." His mouth set into a stubborn line. "And I did not lose."

"Yeah, yeah, 'you should've seen the other guy,' I've heard that before." Castiel glared at him, as if he thought Dean had accused him of lying and Dean chuckled. "Joke, Cas. That was a joke." Castiel looked away, and Dean thought he almost looked embarrassed. When Dean made to move his hand away he felt Castiel's breath catch; he cocked an eyebrow but kept his hand curled against his side. "I don't believe you were complaining about your head with your ribs in that shape."

"I never claimed they didn't also hurt."

Dean shook his head. The swelling around his eye had gone down enough for it to fully open, which only let Dean see that it looked like whatever he'd been fighting had tried to claw it out. "Can you even see out of that?"

Castiel didn't respond, which was all the answer he needed. Dean just hoped he'd been right that the thing had only tried; considering how fast he healed it was entirely possible it had succeeded, and Dean didn't want to imagine that. He focused on the soft rise and fall of Castiel's chest under his hand. "Do you even really need to breathe?" he said, the thought just occurring to him.

"Not...technically," Castiel admitted. "I can maintain my vessel through my Grace, although it would be a strain."

"How long can you keep that up for?"

"Indefinitely. In theory."

Dean's eyebrows raised. "So...wait, if you got dropped in the ocean or...I don't know, buried alive, you'd be fine?"

Castiel really didn't look like he was pleased with this turn of conversation. "I could put myself into a stasis if I found myself in that sort of inescapable situation," he said, not sounding nearly as sure of himself. "Although I would prefer to not be put to the test." He tipped his head to the side, his eyes studying Dean's hat. "I've never understood the importance humans placed on their birthdays."

Dean frowned. "What do you mean? It's day one, "Welcome to the world, Dean Winchester."

"But it's not when you were created."

Dean whistled. "Careful you don't say that kind of thing around the wrong person, Cas."

Castiel shook his head. "That's not what I meant - although yes, it would make as much sense to celebrate your conception -"

"Dude. You're just full of the awesome mental images today."

"-or the day the cherubs linked your parents together. One is just as valid as the other." He sighed. "I'm puzzled by the celebration of the transitory. The creation of your body has nothing to do with creation of you. Your substance is your soul, and that was created long ago."

"Yeah, maybe," Dean conceded, "but humans don't think like that. We want to celebrate something, it has to be a little more tangible. And besides, lots of people don't even believe in souls." Castiel gave him a look so astonished Dean almost laughed, like he'd said people didn't believe in air. "And even the ones who do, it's not like we know when our soul's birthday was, you know. So you celebrate the concrete things: your first day, your first breath, that kind of thing."

"First breath," Castiel murmured. "Since taking a vessel I can see the importance of that." He was quiet for a while, his expression thoughtful. "I don't know when I was created," he finally said. "We don't celebrate personal milestones in that way."

"Yeah?" He lightly brushed his thumb across Castiel's bruised ribs. "That still hurt?" he said, relieved when he shook his head. He got up and got some warm water and towels."So, are we talking before we had calendars or...I don't know, before there were people...?"

"Before there were days, Dean," he corrected.

He sat back down and started washing away the dried blood, going carefully over the still-tender spots. It distracted him from trying to wrap his mind around something being that old - let alone something that old lying beside him in a by-the-hour motel bed bloody and bruised. "Could you find out when you were created? Are you curious?"

"Not especially. It's only..." He sighed. "I'm beginning to understand why humans mark their years by holidays. It would be...pleasant to have a reason to celebrate."

There was more dried blood caked in his hair. Dean was careful but Cas still hissed when Dean touched him; Dean guessed whatever had done the number on his ribs had cracked his head in too, which sure as hell explained why it hurt so damn much. It turned his stomach to hear Cas sound so defeated but he didn't know what to say; giving advice on fighting angelic civil wars was way above his pay grade. Besides, he knew Cas didn't want his honest opinion, that his idiot brothers weren't worth all the hassle. "So pick a day." Castiel glanced up at him, puzzled, and Dean continued, "You don't know when you were created, so pick a day and celebrate it then. If it really was 'before there were days' then one's just as good as another."

"Just pick one?" he said, sounding reasonably certain it couldn't be that easy.

"There's no law against it, Cas. I promise." He cocked his head to the side. "How about the day you came back from the dead that first time? That was sort of a birthday."

Castiel shook his head. "It's too associated with Lucifer's escape. The same with my second resurrection. I don't want to celebrate a day tied to sorrow." His brow furrowed. "I could..." He glanced at Dean. "Would it be all right if chose the day of your resurrection, Dean?"

Dean blinked. "When you yanked me out of hell?"

Castiel nodded. "Yes. Our first meeting."

That was...actually weirdly flattering. "Um. Sure, Cas, if you want." He let a beat go by. "Why?"

"Our meeting drastically altered my destiny. I would be very different had one of my brothers been chosen to retrieve you from hell in my stead."

"You'd probably have been better off. Definitely would have exploded less often."

The corners of his lips tipped up. "I very much doubt I would be alive if we hadn't met, Dean."

Dean felt a cold band wrap around his stomach and did his best to ignore it. "How do you see that?"

"Uriel's scheming would have taken place no matter who was chosen to retrieve you, and there's no reason he wouldn't have still asked me to join him. to believe I still would have refused."

"'Course you would have."

He could tell Cas appreciated the vote of confidence. "Had I refused, he would have reacted the same. And I doubt in this case there would have been a last second rescue."

"You don't know that."

"There was no rescue for the seven of my brothers and sisters he killed."

Dean couldn't fight down the image of Uriel standing over Cas with his sword drawn. "He wouldn't have gotten away with it."

"You wouldn't have known me, Dean. Let alone cared to avenge me." Dean felt his insides churn. He liked that idea even less, Cas dying alone and unmourned with Dean never even knowing to be pissed off. "In fact, if I had agreed to join him, we would have been enemies."

The only thing worse than imaging someone trying to put a sword through Castiel's chest was the thought that in some reality he might be the one trying to do it. "Good thing you met me, then. Saved your life." Castiel huffed out a breath that was almost a laugh. "So, we know what day to break out the party favors for you, then."

"That was in...September," Castiel said, Dean watching him match the Earth calendar to whatever it was they used in Heaven. "And this is January." His expression fell. "That's a very long time."

"Little over eight months. What, Mr. Older-than-the-Earth can't go that long without a party?"

Castiel looked away. "A lot happens in eight months."

Dean turned his head back to face him. "You're still gonna be around in eight months, Cas. And I'm gonna throw you one hell of a party to make up for lost time. You got that?" Castiel looked more than a little alarmed about what Dean throwing him a party would mean. "And besides, if you're really in a party mood, today is still my birthday."

Castiel's eyes brightened. "That's true." Then he looked up at Dean, frowning. "Do I have to wear a hat?"

"Yes," Dean lied. "Absolutely. It's vital." Castiel looked almost as appalled as when Dean had dragged him to that brothel. "But that can hold off until your noggin's healed up."

"It feels better."

"Yeah?" He traced his his fingers through Castiel's hair; Cas took a deep breath but didn't flinch away like last time. "You're getting there." Dean kept his touch feather-light as he stroked his hair. "We've got to have you in tip-top party shape."

"There's also exchange involved," Castiel said, his brows drawing together. "I didn't bring you anything."

"Hey, you showed up." He kissed Castiel's forehead, feeling the tension melt away under his lips.

"But I'm supposed to bring you a gift. Isn't that...oh," he breathed as Dean kissed along the edge of the bruise.

Dean kissed across his brow, switching to careful, light touches around his still swollen eye, down his cracked and tender cheekbone. Cas' breathing shuddered and Dean pulled up, letting his breath linger on Castiel's skin. "Let me know if something hurts."

He felt Castiel's fingertips trail down his spine. "You won't hurt me, Dean." His voice had deepened into a rough, throaty rasp and Dean had to pause for a second to collect himself. It didn't matter how many times he heard it, Cas' voice sounding like that always damn near undid Dean.

He levered himself over Castiel, careful to to keep his weight off of his still-healing ribs. He kissed his way down his torso, paying careful, soothing attention to the sore spots, those stretches where the bruising was still dark and angry. Castiel arched against him and Dean was so hard already; each time Castiel moaned Dean could feel the vibration against his lips.

Dean licked his way back up his stomach and across his chest, flicking his tongue against the hollow of his throat. Castiel's whole body jerked against him and Dean laughed. He traced the edge of Castiel's lips with his tongue until they opened in a sigh; all Dean could think about was tasting him and Cas seemed to agree, grabbing a handful of Dean's hair and pulling him down into a long kiss. Castiel was flushed and gasping by the time Dean finally came up for air, and he sure looked like someone who needed to breathe. "Next time you get your ass kicked, you're gonna call me right away. Promise." Castiel nodded, tipping his chin up to give Dean easy access to his throat.

Dean took the hint, planting slow, wet kisses all the way down, lingering at the hollow of his throat until Castiel made a contented, deep-in-his throat sound that was practically a purr. "Dean," he whispered, his eyes wide and almost inhumanly blue. "I thought...but I'm supposed to get...for you..."

Dean sighed. "Cas." Dean kissed him again, one hand trailing down his ribs before starting in on his belt. "Say 'Happy birthday, Dean.'"

Castiel's eyes crinkled at the corners. "Happy birthday, Dean."

"Good. Now I'm gonna get back to celebrating, if that's okay with you." Then Dean went back to systematically taking apart an older-that-the-Earth-had-days angel of the Lord until the only thing Castiel could think was Dean's name.

Birthdays didn't come much better than that.