Summary: It's a split second choice - probably the only one they have left. But Dean makes it, because it's Cas lying there, bound and beaten, with a bomb strapped to his chest counting down all their deaths. How bad could it be, saying yes to an angel? Season 12 AU

A/N: I am apparently incapable of updating this story on a weekly basis, it would seem. Mind you, Real Life is insane right now with my job trying to kill me via sleep deprivation and stress, but still. I mean, it's already written, all I have to do is remember to post it . One day. One week. I'll get there. I'll be *that* author.

Thanks for all the favs/follows and comments, and hello to the new folk reading just now! Hope you all enjoy my favorite chapter of this story :D

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Cohabitation

Chapter 4

-o-o-o-o-o-o-o-o-

They spent the rest of the week working on the spell. Dean slept through a lot of it once he and Sam were finally able to convince Cas to take control. For practical reasons, was the excuse Sam finally won out with. Dean as the middle man left too much room for error on something as delicate and precise as spell crafting. Especially something as powerful as a golem.

Still, it had included a lot of anger and yelling between the two, Sam was pretty certain, if Cas's guilty demeanor quickly hardening into stoic, solder-like efficiency once he was in control was any hint at how that internal argument had really gone. Sam needed to separate them. Both were too emotionally repressed, guilt-driven martyrs with years of baggage on their backs to ever survive being in each other's heads. Being able to keep their thoughts their own was something that made the three of them functional as a family. The two had needed a heart-to-heart for years now, but they needed it face-to-face, where they could still save some secrets and some emotions from one another. Where they could still feel some things were theirs to keep, theirs to control.

Sam knew what it was like to lose that control, and he knew his two brothers, his best friends, would need it back, and soon.

So Cas took over and Dean slept better than he'd ever slept as just a human, something he hadn't been expecting and Sam was surprised to hear. It certainly hadn't been that way with Lucifer. Although, looking back on it, he supposed it could have been with Gadreel. He had been healing during that time, and when he was awake he didn't recall feeling as tired as he should have, given what it was he was healing from. But Dean swore it was some of the best rest he'd ever had. A couple hours felt like a full night's sleep each time. And not the four hours he was used to, but a full eight. Hell, maybe even ten or twelve (not that he actually knew what that felt like unless it was a crash from an injury or one hell of a bender).

Considering Sam was only averaging about four himself each night, what with all the spell work, research, and most recently sculpting he was trying to get done, he couldn't help but be a little jealous. And as soon as Dean picked up on that, Cas knew about it, which meant the angel was both insisting on small bouts of healing every day now and lecturing him on how he needed to rest more. Turns out, Dean and Cas weren't the only ones who were going to suffer consequences of this new merger.

But back to the sculpting. Because it was their first real problem, it turned out. It hadn't taken long (less than a day, actually) for the brothers to realize that they didn't have an artistic bone between them. Unless you counted drawing sigils, and even then, Cas quietly confirmed that their workmanship actually left a lot to be desired.

'Gee, thanks, Cas,' had been Dean's sarcastic reply, to which the angel awkwardly and apologetically shrugged. It was the truth, as far as angel standards went.

Once they settled on the golem plan, Sam ordered two hundred pounds of clay to start with after extensive research across multiple artists' blogs and clay production websites. Dean flat-out balked at the amount of clay that showed up on at the bunker. And they'd had to tip the delivery guy some serious pocket change to get him to carry it down into the library (and then even more money to keep from him from asking any questions).

His punk little brother used the excuse of not wanting loading the Impala down with that much excess weight ('Wet weight, Dean. Clay's kinda, you know, messy.') but Dean was a hundred percent sure Sam was using his weakness for his Baby as an excuse to get out of hauling two hundred friggin' pounds into and out of a car and into and out of the bunker because he knew he'd friggin' win with it.

And he had, damnit.

Dean was still grumbling about it (Castiel's internal guilt about the money spent was not helping) as Sam explained that they could have done with less clay if they'd be able to use a rebar or wood as a support structure inside the sculpture (apparently called an armature, according to his giant nerd of a brother), but they couldn't do that in this case. Golems had to be entirely made out of clay. Any internal support of another material would weaken the spell and the integrity of the golem's body once created. So there they had it.

Still. A couple hundred dollars later in clay (and a couple hundred more in friggin' delivery fees and bribery) and they discovered the real hurdle. It wasn't stairs or wet weight or loud-mouthed delivery men.

Neither Winchester man could sculpt worth half a damn.

Sam gave it the first try, but it was pretty obvious after he'd gotten the basic shape of a human down that he had no artistic talent when it came to sculpting. He was halfway decent at a drawing now and then, but trees, symbols, things he'd seen. And though he'd spent plenty of the last eight years around Cas, his talents ended when it came to drawing the human face. And carving it was a different matter completely.

Dean, still grumbling and insisting this was a waste of time, gave it a shot as well and his attempt had turned out worse. He managed to slice off half of the face Sam had got going with a little scalpel mishap. Sam didn't even know how he'd managed to do it ('Why were you using a scalpel to start with!? It's a sculpture, not an autopsy!') and had promptly kicked his older brother out of the library where they'd set up shop.

Dean left with a hollered, 'Told you so!' that was entirely as unhelpful as the rest of him had been.

So, Sam was back to researching until he found an artist local enough to drive to them and desperate enough to work under some pretty weird conditions. Turns out, art school was expensive and there were several students in the state of Kansas ready to sign up for a no-questions-asked sculpting gig if it got them paid. Sam settled on a young woman a couple of towns away who had an impressive portfolio, a relatively low hourly rate, and four years of student debts to pay off. He met her in downtown Lebanon at a café for some neutral ground, explained what he needed and had her sign a completely bogus nondisclosure agreement he'd whipped up to make him and Dean look like some trust-fund babies with some serious money and some even more serious privacy issues.

The artist agreed with only the occasional weird look, and Sam had her follow him back to the bunker. The weird looks continued, but she didn't say anything more than to warn them she had pepper spray in her bag in case this was some sort of freaky abduction, sex-slave-in-the-underground-apocalypse-bunker sorta thing. Sam laughed awkwardly, Dean just smirked all tight-lipped, and Sam promptly moved them on.

Dean handed her a photo of Cas – the same one they'd used for his FBI badge – and another of his full frame, from the time he'd gone Godstiel on them and CCTV had captured him on camera murdering a bunch of people. The Winchesters were kinda hoping this kid was a tad too young to have been watching the news at that time.

(They really should have taken at least one photo with the guy over the last eight years. At least, one they hadn't burned.)

Lucky for them, she didn't recognize either photo, and pretty much got to work with no questions asked. Sam showed her the nearest bathroom, the kitchen, and even a room she could crash in if she wanted to sleep there. Not that she had to, he quickly added when she gave him that look that he was pretty sure was her rendition of sizing him up for serial killer material. It was there if she needed it, otherwise come and go as she pleased, so long as she didn't bring any attention to their home or tell anyone where she was or what she was doing.

"I'm pretty sure that's what the NDA was for," she'd replied dryly before heading back to the library and the pile of half-formed clay. Sam followed along awkwardly, settling himself at the table to resume his research (though, far enough away from her little workshop so the book titles weren't readable and he could pull out some normal reading material as cover if she wandered over).

He watched her on and off (still awkwardly) for the first couple of hours, but the woman seemed genuinely intent in her work ad serious about that no-questions stuff. So Sam went back to tweaking the spell, grabbing Cas when Dean wandered back in a couple hours later, and the two settled into spell crafting with their artist working on his visage in the corner.

-o-o-o-

It took three days, but their artist created a pretty damn good look alike. It cost them another several hundred dollars – half a friggin' fortune, Dean grumbled at that point – by the time she was done. Which had Dean continuously muttering 'stop apologizing' aloud to himself over and over again. But by that third day they had a clay figure with an uncanny likeness to Cas.

"That's just…freaky," Dean said as they stood in front of the life-size sculpture, having escorted the woman out of the bunker with her handful of cash. Sam glanced over at him, and he could practically see the head tilt Cas was making somewhere inside Dean's head.

"She did a really good job," he agreed, staring at the colorless rendition of their friend. "It should be enough to pass as human once we get the spell attached. Speaking of."

Sam went over to the end of the library table and snatched a small scroll of the table, rolling it up into a tube as he headed back over. He'd spent the whole night writing the spell out on the thin, long sheet of parchment they'd had to purchase specially for the spell. Cas had stayed up with him, occasionally staring wide-eyed from Dean's face at the artist putting the finishing touches on, well, himself.

Man, the look that woman had given them when they'd asked her to sculpt their friend with an open mouth, tongue up, was…well, even Sam had blushed and it had gotten awkward.

"We gotta ask her to do what?" Dean had practically choked on his scrambled eggs when Sam first brought it up. Then again, maybe he should have known better than to bring it up over breakfast.

"That's where you put the scroll to make a golem, Dean," the younger Winchester explained, exasperated. "Under the tongue."

An absolute fortune. That was what a no-questions-asked, under-some-weird-ass-conditions, am-I-making-you-some-fucked-up-sex-toy-made-out-of-clay?, sculpture cost these days. Dean just muttered more and sharply told himself to apologizing, it wasn't his fault.

Yeah, the woman they'd hired had taken to avoiding Dean since day one.

With a deep breath and a hopeful glance at his brother, Sam stepped up to the clay sculpture and slipped the scroll beneath the carved tongue. Given his height over the Cas-look-alike, Sam saw the scripture light with shimmering red power, the words glowing like embers. That light quickly spread throughout the clay figure, and the words Sam had written on the parchment appeared across every inch of the clay, lit with the same waves of red.

They faded as the grey of the clay started to fade into other colors – fleshy pinks and tans and blues and blacks that filled out the sculpted trenchcoat, suit, tie, skin and hair. As the last of the grey disappeared for realistic looking skin and fiber, the sculpture's eyes snapped open a fierce blue and Sam and Dean took a surprised step back at the sudden movement, the older going for the gun tucked into the back of his pants.

But Clay-Cas didn't move further. There was life there, of a sort, as it stood still, non-moving, non-blinking, but…fleshy.

"Okay, that's creepier." Dean released the butt of his gun slowly. It took a couple of minutes before he was convinced the thing wasn't going to attack them, or move at all (he probably would shoot it if it did out of pure horror-movie survival principles). The way not-Cas just stood there, staring, reminded him too much of Cas under Naomi's control. He was not a fan.

Which, of course, Cas picked up on and Dean could feel the responding guilt, shame, and self-loathing. Neither of them had said a single thing, but now Cas was miserable and Dean was frustrated because it wasn't Cas's fault – either then or now – and he never meant to bring it up.

Sam was right. This was going to drive them both into an early grave.

"It should be less creepy once we get Cas inside." Sam turned towards the angel/brother duo with a grimace that was probably supposed to be an encouraging smile. "Time for the last ingredient."

And the part all parties were looking forward to the absolute least.

'You should get some sleep first, Sam,' Cas spoke up from within Dean, trying to push his own mixed emotions and trepidation aside at the memories that grace extractor always brought up. Memories he could mostly keep from Dean as an angel possessing a vessel, but feelings seemed to slip right through in his drastically weakened state as an angel with barely any grace left to wedge between him and his human charge.

Dean relayed the message and, though Sam seemed hesitant and it took several convincing arguments, the younger Winchester reluctantly agreed. So they left the creepy-ass, life-like Cas just hanging out in the corner of the library (Dean did not trust it and would certainly be sleeping with a gun under his pillow tonight) and headed for the dormitory wing for a couple hours rest before the big event.

-o-o-o-

The next morning, with both humans refreshed and feeling at least halfway decent (Sam with the hope of freeing both his brothers, Dean who was honestly starting to lose his mind, and Cas who was very much done with feeling nothing but feelings over the last week and a half) headed down to extract Cas's grace from Dean's body. Sam strapped Dean down onto the infirmary chair quietly, stewing in his own unpleasant memories of how much this would hurt. He set the box with the oversized needle on the tray beside the chair and braced himself for what he was about to do.

"Just get it over with, Sammy," Dean griped, not liking the air of trepidation that was all around him (and inside him thanks to his resident angel). "Like ripping off a band-aid."

He regretted those words the minute Sam pulled the syringe out of its case. That was one hell of a band-aid.

Dean's fingers dug into the armrests of the chair as tension filled him that was mostly not his own, but he grit his teeth and kept quiet. He was doing this for Cas. Cas and his own sanity, but mostly Cas. He could feel the angel's own trepidation, and Dean forced himself to relax, telling Cas to do the same. Tensing was going to make it worse.

Sam took a deep breath, lining the syringe up with his neck, just below his ear. With a deep breath and a last word of advice – "Try not to move" – he started the slow descent of the needle into his brother's skin.

The pinch hurt, as did having a friggin' needle the size of a damn straw stuck into his skin. Dean grit his teeth through it, but overall thought, 'This isn't so bad.'

Unfortunately, he heard Cas's unintendedly voiced, 'Just wait,' right at the same time Sam settled the needle in as far as it needed to go.

"Okay," his brother breathed out, the shakiness in his voice an outlet for his rock-steady hands. "Here we go."

Then he started to pull the plunger back and Dean's grip into the chair became white-knuckled, then shaking-knuckled, and then shaking-the-entire-armrest, as fire erupted in his neck and through his body like white-hot blades. He could feel it down to his toes – every inch of him – sucking the very life out of veins (and the air and the muscle and the tissue and everything that made up everything he was and suddenly Dean understood how every character ever sucked out into space through a hole in a spaceship felt) as Sam started to extract Cas's grace from his body.

Flickering white-blue light spurted into the syringe in little sputters, and Sam had to fight back the disheartenment at how weak and grey that once powerful light now was. It sputtered in the syringe, more filling the glass container than he remembered with Gadreel, but still less than a fourth of what the cylinder could hold.

"S-Sam-" Dean's voice through his gritted teeth and compressed jaw was raw with pain. He could barely breath, and he could feel how much worse it was for the angel inside him.

Sam ground his own jaw as he kept pulling at the plunger. "Almost there, Dean."

"N-No," his brother sputtered. His fingernails were staring to bleed with how hard he was holding onto the chair and he would have bruises from the restraints. "You g-gotta st-stop."

"I've almost got it!" Sam pulled the plunger a little faster, seeing the first specks of red blood enter the syringe with the trail end of the grace.

"Sam, st-stop!" his brother practically screamed, arching his back. "It's- It's killing him!"

The younger Winchester fumbled the syringe as he let go of the plunger, heart hammering in his chest. It took every ounce of his self-control not to withdraw the needle or let his hands shake as desperately as they wanted – needed – to. "Dean?"

Still arched across the chair, his brother was heaving with uncontrolled pain. "You gotta put it back," he moaned, eyes mere slits that pleaded with his brother. "It's k-killing him, Sammy."

"I'm almost there, Dean," he whispered – pleaded – back, eyes darting between the syringe of glowing light and his brother's ashen face.

Dean shook his head the best he could, neck muscles bulging in agony and veins throbbing in his face and throat. He could take the pain, but he couldn't take hearing his friend screaming inside his head. There was no barrier between them, no way to muffle his pain, and Dean knew to his very core that if they continued, Cas wouldn't survive it.

"We'll f-find another way."

The younger Winchester fought back the overwhelming urge to just finish it, to rescue their angel and free his brother, but he couldn't do it. Sam trusted his brother. Even being so close, even knowing one more pull and he'd have all of Cas, he couldn't do it. He knew Dean; pain wouldn't make his brother stop. But Cas's pain – Cas dying – would.

Sam breathed out pure defeat and he couldn't keep his hands from shaking, but he nodded roughly and started to push the plunger back in. Dean couldn't quiet the scream that finally tore out of his throat as that fire re-entered his system, ragged and torn on the edges, ripping it's way through his body with nothing to dampen the pure power and savage pain of another's essence overtaking his body.

The last of the grace vanished as Sam fully depressed the plunger and Dean's eyes lit blue with the completion of the possession, even as a second scream tore from his throat. The lights above them burst, sending sparks and shards of glass raining down on them. Castiel's grace lit the room in a flash of blue-white before everything fell silent.

Sam couldn't contain the broken sob that ripped at his own throat or his panic as Dean lay completely limp and, for several terrifying seconds, Sam had no idea if he'd just killed both his brothers.

-o-o-o-

Dean woke up after only a couple of hours. The first of which Sam had sat glued to his brother's bedside (after he'd manhandled the dead-weight of his still-breathing body through the bunker and back to his room) worried he might slip away if Sam wasn't watching. The last several Sam had spent certain that Dean would live but terrified that he'd killed Cas. He had no way of knowing if the angel was still there, and had to tell himself over and over again that there would have been wing prints.

Only, Cas didn't have wings anymore.

He spent those hours alternating between trying to find out where they went wrong, what they could do now, searching for a spell to detect an angel inside a vessel, triple checking the infirmary for charcoal prints of any kind, and sitting in his brother's room watching the rise and fall of his chest with half the library in there with them. Dean would be pissed at the mess of books in his room when he woke up and Sam would welcome it when it happened.

When Dean did finally come to, it was with a hoarse voice and a sore throat. But given his little brother's faintly red-ringed eyes, utter lack of rest, and clear worry, he quickly reported that he and Cas were both okay.

"What happened?" Sam asked roughly, closing the thin and only manual they had on the grace extractor, written damn near a hundred years ago and all but buried in the bunker's archives. And also pretty damn useless.

Dean just shook his head, blinking away the raw emotion and memory of those screams. God, he never wanted to hear Cas like that ever again. But, while the angel was weak and sounded small in his head, he was still answering Sam's question. "He says his grace was too weak. The pull from the syringe was tearing-" Dean cut himself off, swallowing through a lump of pain that was and wasn't his, "-tearing it in half."

Sam looked as nauseous as he felt, but Dean reassured him again that Cas was okay now.

"What do we do now?" His little brother's voice sounded young, and Dean was reminded that even at thirty-something, Sam was, in all the ways that mattered to Dean, still just a kid sometimes. A kid who was terrified for his brother and his best friend, and had wielded the thing that nearly killed them both, even if it wasn't his fault.

Truth be told, Dean was just as lost and just as worried about it. He hadn't really let himself think about what came next if this didn't work, because it was going to work. It had to work. It was becoming clearer every day that he and Cas might make decent roommates, but they were not gonna work out as head buddies. Dean needed his… well, space. And Cas…god, Cas was carrying around just as much damn guilt and hurt as Dean, and the hunter had already been on that precarious edge of having as much of that shit as he could handle on his own. Together, it was a straight up martyr fest of misery in there right now.

Dean snorted internally. What a pair they made.

'Indeed,' Cas agreed, his voice as wry and bitter as it was endearing and amused. A perfect match to Dean's own mood.

"We'll figure this out," Dean said aloud, because he meant it for the angel, but he also meant it for his own brother. Because they would. Yeah, this was going to suck, but they'd make it work. Really make it work, not just tough it out until they found a solution, because as terrifying as it was, Dean and Cas were both realizing that there might not be a solution.

Did he mention that was terrifying as all getout?

But he'd be damned if he was going to let Sam see any of that. Or his angel (well, more than what was already on the table because they shared a friggin' body and he couldn't hide anything.) So he pulled on his big brother face, set in stone and determination, and told them both that they'd figure this out. "We'll give Cas a chance to heal his grace," he offered, knowing what that meant for both of them. "Maybe when he's stronger, we try again. Or maybe we call in a favor."

They had enough of those that someone ought to be able to help. Hell, worse case they bring in Crowley or Rowena. Dean was reluctant as hell to work with either of those two, but both had proven useful and for Cas's life, any price would be worth it.

Cas seemed far less sure, but Dean just sent more of that big-brother determination towards the angel in solid waves of 'shut up and listen to me' that seemed to amuse the angel as much as it consternated him. Still, amusement was something the hunter would take over guilt or pain any day, so he went with it.

Sam settled back in the chair he'd dragged in from the library. He looked as torn as Castiel felt, but he offered up a weak smile to his two brothers. "Alright. I'll um…I'll make some calls."

"Tomorrow, Sammy." Dean sagged back into the bed, realizing just how exhausted he was even after the forced unconsciousness. "Right now, I call timeout for a breather."

When Sam nodded way too readily, standing and starting to gather books into his arms (and Jesus, did the kid bring the entire bunker archives into his bedroom?!), Dean frowned. "That means you too. Don't think I can't see those bags under your eyes. So sit your ass back down or go to bed, but no more research."

He angled a look at his kid brother that might have been demanding but was also knowing. It promised a return to the books tomorrow, without complaint even, but rest for today.

Sam's gigantor shoulders sagged, but he lowered the books back into their piles and all but collapsed back into the chair. Dean had a point, even if Sam was dealing with his own fair share of guilt and driving need to fix this. And his brother looked about ready to pass out, and Sam knew he would climb his exhausted butt out of that bed and force Sam into his own if he didn't just agree, so that's what Sam did. He agreed, and he spent the next several hours watching over both his brothers before finally crawling off to catch a few hours of rest himself.

(With maybe just one bunker book in hand. In case he couldn't sleep, of course.)