A/N: Last chapter!

Chapter Eleven:

The Butt Slap Protocol

The heavy, metal door to the bunker clanged open, and the sound echoed through the War Room below, disrupting the quiet only for a moment before silence fell once more.

Dean shook off the chill that went through him as he stepped over the threshold, the same chill he'd felt walking down the deserted streets of Eufaula. Lifting his left shoulder so his duffel bag didn't slip down, Dean took the stairs slowly, keeping a firm and steady hold on the crate of beer bottles in his arms. Cas followed behind with the second crate, and Sam took up the rear, laden down with all his stuff as well as Dean's weapons bag.

"I don't wish to underestimate you," said Cas as he lugged his crate onto the map table, "but are you sure you'll manage to drink all this."

Sam smiled, eyelids drooping and hair mussed from his seven-hour catnap. He still looked tired, and there was tension in his shoulders and a strained note in his quirked lips, but at least he was back to making eye contact. "Don't make it sound like a challenge, or Dean'll finish off the lot in record time."

Dean's brow furrowed with mock affront, the illusion ruined by the wink he threw his brother's way. "I'll share."

Sam shook his head and bit back a yawn only for his gaze to catch on the patch of floor where Maggie's body had fallen after Michael's attack. The blood had been cleaned up, leaving the space unmarred, but even Dean's mind brought up the memory of Maggie lying there, scared and broken, her eyes burnt out and her life taken by the monster she'd crossed worlds to escape.

Any hint of a smile left Sam's face. He cleared his throat, shook his head, and left the room without another word. Dean stared after him, his heart squeezing tight in a way it hadn't in a long time.

Empathy was a bitch.

"Will he be all right?" asked Cas, his voice low enough not to disturb the ghosts that remained.

Dean turned away from the door his brother had left through, lightly tapping his tight fists against the table. "He'll bounce back. We always do."

Cas's eyes softened with sympathy, and it made Dean shift, discomfort rolling through him at being the object of pity. He tore his gaze away and grabbed two of the make-shift beer bottles, handing one to Cas who shook his head.

"I think I'll avoid alcoholic beverages for a little while," he said.

The feeling was mutual, but Dean wouldn't admit to that because if he did, he'd be broadcasting that something was wrong, and they all had enough to deal with at the moment. So instead, he nodded at the cargo they'd carted in and asked, "And let all this go to waste?"

Cas glanced over the crates and smiled up at Dean. "I'm sure you'll manage without me."

Dean's gut twisted. A 'no, I won't' rose to his lips out of habit, but he pushed it down. This wasn't a life-or-death, rallying-the-troops-before-a-final-battle moment of candour. Going all chick flick would make things weird. He uncapped the bottle and downed a swallow. The bitter taste sat on his tongue, and he rolled it around his mouth, savouring it even if the beer was a little on the tepid side. At least Sophie's reversal spell hadn't affected the quality.

Over on the other side of the table, Cas shifted, rolling his shoulders and cracking a kink out of his upper spine. He looked stiff and uncomfortable and kept shifting his weight. Dean would have blamed the seven-hour drive, except Cas had driven for longer stretches of time before now and walked it off like it was nothing. Short of a demonic or angelic showdown, Dean wasn't sure what could make an angel ache, but something had obviously managed it last night.

His chest tightened, and he blamed the hangover that was still roughing him up. He took another sip of beer and picked at a spot of rust on the map table, keeping his tone casual as he asked, "So what impulses does an angel have?"

Cas went rigid. His shoulders tensed, and the rest of him went very still while his gaze dropped and turned inward. Dean almost felt bad for pushing the angel's focus to the blank spaces in his memory, but the curiosity ate away at him. He needed to know what Cas had got up to last night.

Cas eventually glanced back Dean's way, but he did so without raising his head. His chin rested close to his chest, and he looked almost demure in his uncertainty. "I don't know, Dean." He tilted his head a fraction. "What impulses do you have?"

Heat flooded Dean's cheeks as the pleasant ache thrumming through him, dulled by the long drive, returned. He had to force his eyelids not to flutter shut, and he held his breath as a sigh tried to make its way out. Cas watched him with squinting eyes, and Dean averted his gaze. He did not want to be discussing his rough, kinky, mystery sex with Cas, so he chugged more beer, grabbed another bottle, and headed for the door to the bedrooms, muttering a quick, "Don't know."

Dean swore he could still feel Cas's gaze on him even as he shut the door behind him and leaned against it with a drawn-out sigh. It felt like his bones had taken permission from his brain to revisit last night, going all achy and cottony at the same time, but he shook it off. The last thing he needed was to be caught out in the open with his eyes closed and bliss written all over his face.

This case hadn't been all bad. He was willing to admit that much. Hell, there was some of it he might actually miss. The green light Sophie's potion had given him to do whatever he wanted without fear of repercussions or judgment had felt freeing, and even if he couldn't remember what he'd done, that feeling stuck with him. But not knowing was killing him. It was bad enough when other people lied to him and kept secrets from him, but now he was doing it to himself, too.

Eyes squeezing shut, he shook his head and moved on.

Beers in hand, he started down the corridor, intent on getting a couple hours of sleep before he dragged his toolkit out to repair the Impala. Imagining her sitting outside the bunker, forlorn and broken, made his insides hurt, but he couldn't risk fixing her with his eyelids drooping the way they were.

Walking through the rats' maze that was the bunker, he passed Jack's room and stopped. Not a sound came from the other side of the door, and he figured the kid might be sleeping. His arm twitched, and he almost gave in, almost knocked, almost woke Jack up so he could apologise for letting Michael out. He squeezed his fingers into a fist and shook his head at the selfish desire to disturb the kid's rest in favour of easing his own conscience.

He got to his room only to stand in the doorway and stare at his bed. Even as the comfortable mattress and warm sheets tried to lure him in, his earlier exhaustion fell away in a fit of twitching fingers and bunching muscles. His mind whirred with a second wave of energy that he'd thought was beyond him at this point.

With a shrug, he grabbed his toolkit from beneath his desk and headed back the way he'd come.

Hours later, the Impala gleamed. Polished and waxed, the black coat of paint shone, and the new hubcaps glimmered beneath the garage light. Dean didn't have the glass to replace the windows, but he'd make a pit stop next time he went out. For now, Baby looked close to brand new, and he was damn proud of the work he'd done on her.

"She's looking good," said Sam as he jogged up the steps, his laptop clutched beneath his arm.

Dean barely spared his brother a glance, too busy admiring his handiwork. "That she does." Sam stepped up next to him, and out of the corner of his eye, Dean caught him wincing and rubbing his ass. "What's wrong with you?"

"Nothing." His brow furrowed, and he cleared his throat. "Cas, uh—he slapped my butt."

It took half a second for Dean's brain to make sense of that information, and when it did, his burst of laughter came out as loud as a shout. Sam shook his head, hiding a thin-lipped, grudging smile that threatened to become more. "Sure, laugh it up."

"I'm sorry," Dean said, the words coming out breathlessly while he tried and failed to school his features. "He—he really…?"

Sam nodded. "Yeah. Did it hard too."

The expression on Sam's face forced another whoop of laughter out of Dean, and he had to turn away.

A memory popped into his head from last night of him and Cas in the motel room as Cas asked about the purpose of butt slapping. Dean had given the best answer he could think of, but in hindsight, he'd left a lot of room for misinterpretation.

His laughter stopped, and Sam glanced over at him with a concerned tilt of the brows. Dean brushed it off by taking the rag he'd stuffed in his back pocket and rubbing at a pristine spot on the Impala's hood. Dismay settled in his gut as he thought over the fact that he was going to have to explain to Cas the proper butt slap protocol or else risk being on the receiving end of that open palm.

"What d'you got there?" Dean asked, nodding at Sam's laptop and distracting himself from how much he was not looking forward to his upcoming conversation with Cas.

Sam shifted his computer from beneath his arm and almost set it down on the Impala's roof before a low sound from Dean convinced him to rethink that plan. "A new case," he said, flipping the computer open. "A dead undertaker and desecrated graves. I'm thinking ghoul."

Dean watched his brother, the way Sam looked fixedly at the computer screen, once again stubbornly refusing to make eye contact. Dean had known one case wouldn't be enough, especially one that had ended with such minimal bloodshed. Sam needed more, and he was itching to get it. Dean nodded and tossed the rag into his open toolbox.

"Grab your stuff," he said. "Meet back here in five."

A/N: And there we have it! What did you guys think? Does Cas remember? Does Dean remember too—if only subconsciously?

I hope everyone enjoyed the story, and if you did, keep an eye out after season 15 ends because I've got a bunch of spn fics lined up!