A/N: Another angsty "what if?" I don't own Supernatural or the lines lifted from 8x17 "Goodbye Stranger." At the moment, this is a one-shot, though I hope the muse will add more to it eventually.

"Hello Stranger"

"We should let him out of the dungeon."

Dean jolted from his blank stare and blinked at his brother. "What?"

Sam gave him a canted look. "We can't keep him in there forever."

"I know that," he replied somewhat irritably, and snatched up his half-empty beer bottle. The brew was lukewarm and failed to wash down the bitter taste in his mouth. "And if he tries to fly off? Or attack us?"

"We've got sigils all over the place. No angel is getting in…or out. And I think he would've tried something by now if he wanted to hurt us." Sam leaned back in his chair with a sigh. "Dean, we have to do something."

"Kevin is working on the angel tablet. If there are any answers, that's where they'll be. So in the meantime, we can just sit around twiddling our thumbs."

"We could talk to him."

Dean pushed himself to his feet a little too quickly. "He's not Cas." He lifted the bottle to take another swig, forgetting how bad it tasted. Shaking his head, he turned and strode for the kitchen. But dammit, Sam wasn't going to let this go, for his little brother was up and on his heels.

"He's in there somewhere, Dean. He has to be. He stopped himself, before he…"

Killed you.

Dean rolled his neck, remembering the snap of bones, the anvil fists pounding his flesh, the copper taste exploding in his mouth.

"Cas. I know you're in there. I know you can hear me."

Cas, his friend, angling his angel blade up to drive into Dean's chest.

"We're family. We need you. I need you."

Cas's fingers letting go and metal clattering on the floor. And then his hand reaching toward Dean's face. Dean begging him, realizing that this was it; Cas was going to smite him.

Only, his touch had mended torn tissue and shattered bone, taken all the pain away—the physical pain at least. Dean had blinked up at him in bewilderment.

"I'm so sorry, Dean." Cas said miserably, even as blood began streaming out of both his eyes.

"Cas?"

Cas reached up to hold his head. "Take the tablet and go! Before she comes." He flinched as though something had struck him.

Dean's hand twitched with the urge to reach out. He didn't though, having no clue what the hell was going on. He could only watch helplessly, unable to fight an invisible enemy…and who was his enemy anyway? Cas? Or this Naomi?

Cas stumbled back a step and curled in on himself. "I can't stop her, Dean. She's controlling me, and I can't stop her."

Dean's heart dropped into his stomach. And then Cas's gaze fixated on something on the floor, his posture going rigid. Dean stiffened, immediately searching for the tablet. He spotted it among the bits of broken rock a few feet away, but that wasn't what Cas lunged for. It was the angel blade.

And Dean had stood there, frozen, heart clenching with the belief that the beating would start all over again. Therefore he didn't fully process when Cas turned the blade on himself. He didn't move or shout when Cas slammed against the wall, blood pouring from his nose now too, hands shaking as he appeared to be fighting some invisible force preventing him from stabbing himself. Dean had no doubt Cas would have won—the look in his eyes as he met Dean's stunned gaze was so full of heart-wrenching desperation followed by steely determination—but Sam had arrived, and, acting quicker than Dean, knocked Cas out from behind.

Sam shot him a frantic look, but didn't waste time. "We got to go—now."

"Dean?"

He tore himself from the memory and blinked. "What?"

Sam heaved a sigh. "Were you listening?"

Dean dumped his stale beer down the sink. "I heard you, Sam. I just don't think there's any point."

"What the hell is wrong with you? You're giving up on Cas, just like that? This wasn't his fault!"

"I'm not giving up on him!" Dean smacked his palm on the counter. After a moment of regaining control, he rubbed a hand down his jaw. "And I'm not blaming him for what happened." No, he was blaming himself. He'd known, ever since Samandriel, that something had been off about Cas. How had he gotten out of Purgatory? How could he not remember? And what had Dean done? Nothing. And why? Because he was pissed at Cas? For the Leviathan, for Sam's wall, hell, even for choosing to stay behind in monster land?

Well, now he was the only one nursing those sore spots, because the angel who had apparently erased Cas's memories of escaping Purgatory had done a whole lot more than that. It'd been a week, and Dean and Sam were confident this bitch couldn't reach Cas in the bunker, but the damage had been done.

Cas lifted his head, eyes slowly opening to gaze around the dark room. He paused at the Enochian sigils painted on the walls and floor underneath the chair he was chained to with spelled manacles. The Men of Letters sure had their resources. Cas frowned, giving the cuffs an experimental tug. Then he looked up at Dean and Sam standing in front of him.

"Hey, Cas," Sam said softly when it was clear Dean wasn't going to speak. "How are you feeling?"

Cas roved his gaze around the room again. "What do you want?"

"Uh…" Sam's brow furrowed. "Well, for starters…um, do you still feel the urge to kill Dean?"

Cas stared at them for a long moment. "Who's Dean?"

Sam approached the bookcase concealing the dungeon with apprehension. It just felt wrong for Cas to be locked up inside there. He'd been stoic and laconic since waking up, more or less like the emotionless heavenly soldier of few words they'd met four years ago. He hadn't even been hostile at being kept prisoner, though Sam had tried to convince him it was for Cas's protection.

Taking a deep breath to steel himself, Sam pulled the knob for the racks to slide apart. Cas sat with his back straight in the chair, head held up and staring unblinkingly ahead. He cocked his head ever so slightly as Sam entered.

"Hey, Cas."

"I have told you many times, my name is Castiel." He looked away, almost with a hint of exasperation. "I do not understand your refusal to address me properly."

Sam held back a sigh as he pulled the chair from the corner and sat in front of the angel. It was a tired argument. Castiel insisted on them using his full name, whereas Sam hoped using the nickname the Winchesters had given him would spark some long-lost memory. So far though, it wasn't working. Naomi had wiped everything—not just the past several years with the Winchesters, or Cas raising Dean from Hell…but everything. Castiel knew he was an angel, knew it was his mission to watch and protect the earth, but that was it. He didn't know the Apocalypse had started and been averted, didn't know that God had left the building long ago, didn't know all the things he'd done while fighting Raphael.

Sam rested his arms on his thighs, interlocking his fingers. "It's a term of endearment."

Cas did that bird-like head tilt thing.

After a prolonged moment of silence, Sam spoke again. "I was thinking it's probably real uncomfortable in here. Maybe we should set you up in a proper room."

"You should release me."

Sam shook his head. "Naomi's still out there, and we can't risk her snatching you up again." Though what more could she possibly do to shatter their lives?

"Kevin's working on deciphering the angel tablet, and we'll find a way to fix you, I promise," he continued, chest constricting. The words sounded so similar to the promise he'd made to a mentally unbalanced Cas, one who made sandwiches and collected honey from bees.

Castiel straightened back to his ramrod posture. "I am not broken. Your insistence otherwise is unfounded and baffling."

Sam bit his lip, and after a moment, tentatively reached forward to place his hand over Cas's. The angel angled his gaze down to regard the contact curiously.

"I know you don't understand right now…" Sam swallowed around a lump gathering in his throat. "But you're family to me and Dean, and we're not giving you up. Cas. Castiel."

The angel simply stared at him as Sam drew out a key and bent over to unlock the shackles. He felt a flutter of trepidation as the manacles fell away from Castiel's ankles, but refused to show it as he sat up again and met Cas's eyes. With the sigiled cuffs, he wouldn't be flying off or using any of his angelic powers, but that didn't mean he couldn't attack and beat Sam into the ground.

Cas didn't though, and merely allowed Sam to draw him to his feet and escort him out of the dungeon.

Dean headed back to his room, intending to put on some rock music and blare it in his ears in order to drown out his festering thoughts and guilt. He pulled up short when Sam rounded the corner, Cas in tow. The angel still wore the sigiled handcuffs, though the long chain gave him full range of movement. Dean tensed, ready to leap in should Cas try to make a break for it, but the angel dispassionately entered one of the vacant rooms Sam gestured to. Sam followed, and Dean heard his brother's muffled voice pointing out the bed and desk, and asking if Cas wanted anything to read. When Sam emerged a minute later, shutting the door behind him, Dean managed to relax a fraction.

"You sure about this, Sam?" he said brusquely.

Sam waved a hand sharply for him to keep his voice down as he strode forward. "If he was gonna Zero Dark Thirty us, he would've done it already."

"Cas can be patient."

"He still believes in his mission to protect humans."

Dean snorted. "Yeah, 'cause it's not like good-little-soldier Cas wasn't ready to sacrifice a whole town or nothin'."

Sam threw him a bitch-face. "At this point, he's probably just a flight risk. And I think we have a better chance of winning him back if we try to befriend him. I mean, we did it once before."

But then that was it, wasn't it? They had been friends, family, who had gone through so much together Dean had the emotional baggage to prove it. So how could he just set all that aside and go back to the way things were? He couldn't forget the past few years simply because Cas had. Dammit, this wasn't even the first time he'd had to deal with an amnesiac Cas. So why was this time harder?

Sam's expression turned sympathetic, as though he could read Dean's mind. "You should go talk to him. Seriously, Dean. If he's gonna remember anything, it won't be on his own."

"Has he remembered anything yet?" Dean retorted, perhaps too harshly. This wasn't like last time where smiting some demons helped "Emmanuel" remember he was an angel. No, Cas knew who he was…well, who he used to be.

The shift in Sam's eyes and the drooping of his shoulders made Dean feel like a dick. He rubbed the back of his neck. "Yeah, okay. I'll talk to him."

Sam gave a small nod of encouragement. "I thought I'd find something for him to read, so he's not staring at the wall." He moved past Dean to head for the library.

"Dad's journal," Dean said without thinking.

Sam paused on the steps. "What?"

Dean rolled his shoulder in discomfort. "I dunno. On that case with Fred Jones, when we were still researching, Cas seemed to enjoy reading Dad's journal."

Sam's brow furrowed, but he didn't comment. "Okay."

"Okay." Dean found himself standing alone in the hall, torn between retreating to his own room, and knocking on the door just a few feet beyond it. Anxiety twisted his gut into knots, and for a second, he considered taking the cowardly route. But Sam would be all over his ass until he gave in and actually talked to Cas. Not that he hadn't tried those first couple days, but staring into that utterly blank expression as his best friend didn't recognize him…

Grow a pair, he berated himself, and knocked on Cas's door. After a moment of no response, he knocked again. Now he was getting frustrated. Here he was making an effort, and Cas couldn't even acknowledge him? Dean was about to storm away in anger, when he leaned his head against the door in crushing realization. This Cas probably didn't know he was supposed to answer when someone knocked.

After taking several deep breaths, Dean turned the knob and stepped inside. Cas was sitting on the foot of the bed, arms resting in his lap with the chain bundled under his wrists. He was staring at the wall, and yeah, Sam was right; guy needed a hobby.

Dean cleared his throat. "Hey."

Cas blinked at him. "Hello."

No, "Hello, Dean," and dammit, his eyes were not prickling with moisture. He cleared his throat. "How you doing?"

"I wish to leave."

Dean suppressed a sigh. "Yeah, I know. But—"

"It's for my protection," Castiel interrupted. "So you've said repeatedly. I know you and Sam believe that to be true, but I am an angel. I do not need 'protection'."

Dean ran a hand over his hair. How was he supposed to have a conversation with Cas when it always went the same way? They couldn't let him go, and as long as he felt he was a prisoner—which, dammit, he was—he had no reason to trust them.

"A lot's happened out there, man. Angels have gone rogue, demons have access to angel blades now, Leviathans—" Dean's voice hitched slightly. "Are loose. It's a lot easier for an angel to die."

Castiel gave him a condescending glare. "And two humans think to protect one angel from all that?"

Dean clenched a fist. Oh, he so did not miss when Cas had been a dick that first year they'd known each other. Getting the stick out of his ass had been enough of a challenge the first time around, and now Dean had to do it again?

"Not just any angel," Dean said around a sandpaper throat. "You. Our friend." He held up a hand when Cas seemed about to protest yet again. "Yeah, I know you don't remember. I can tell you all about it…" Well, not all of it, and certainly not some of the more shitty parts, not right now. "But it won't matter 'cause you won't believe me anyway." God, why was he even here? The ensuing silence felt suffocating, and Dean was on the verge of turning tail and running when Cas spoke up abruptly.

"I hear your prayers."

Dean stiffened. "What?" He hasn't been praying, not with Cas down in their dungeon and not knowing him from Jack.

Castiel turned his head to appraise him thoughtfully. "In your sleep, sometimes you pray in your dreams. I hear them."

Dean's jaw went slack. Oh, wasn't that friggin' awesome. What the hell was he even saying in those dreams? All he really remembered was snippets of fighting his way through Purgatory, his stay in Hell, and sometimes Cas beating him to a bloody pulp. Yeah, that was an image Cas needed.

"Your prayers are irreverent," Castiel said haughtily, but then his mouth turned down. "Yet…they are genuine." His brow pinched in classic confused Cas that made Dean's chest want to split open.

"I do not understand," Castiel finally said wearily.

Dean didn't know what to say to that. Hesitantly, he took a step toward the bed, then another. When Cas didn't react, he slowly sat down next to him. "What do I say?"

"Sometimes you are praying for help. That I understand; many humans pray for deliverance in times of trouble."

Dean forced himself not to fidget. "What else?"

Castiel's lips thinned. "Other times you are yelling. I believe you are angry with me. Yet other times you…" His face pinched as though he couldn't find the words. "Are asking if I am okay, and begging me to come back." Cas craned his neck to look at Dean head on. "Why do you pray so much to me?"

Dean felt that annoying lump returning, threatening to choke him. He briefly flashed back to that night in the crypt, when another Cas who'd also been a stranger was staring down at him with that blank expression of nonrecognition. He'd said it then, in a moment of desperation when he thought he was about to die, clinging to some hope so deeply rooted inside him that it couldn't be cut out, no matter what the world threw at them or how much they screwed up.

"Because. I need you, Cas."

Castiel's stare bored into him, down to his soul, just like he used to. It always annoyed and unnerved Dean, but this time he stared back into those intense blue eyes…and there was some flicker there, something fleeting yet very real. Dean didn't dare to hope; but he suddenly wasn't ready to give in to despair either.

Cas turned to face the door again. "Then I will stay."

Dean let out the breath he hadn't realized he'd been holding. It was a start at least. Maybe it would be a long road to repairing what'd been broken; maybe Cas would never truly remember. Either way, Dean and Sam were gonna stay by his side. Because that's what family does for each other.