When Sam was a little kid he was afraid of the dark. There were, he said, "things" out there beyond the edges of light, out where his eyes couldn't see. He was told not to worry. If anything came out of the dark to get him, his father or brother would kill it.

Sam couldn't explain what he meant. He wasn't talking about monsters. He wasn't talking about the things John and Dean didn't talk about – the monsters they hunted. There wasn't anything in a child's vocabulary to explain what he meant because there wasn't much in adult vernacular either. The dark felt different to Sam. It wasn't the same as a monster hiding behind a tree or in the closet. It wasn't the same as the creepy feeling of a haunted place. It was more like the darkness itself were alive.

And it spoke to him.

He heard it whispering, always whispering, but no matter how hard he tried he could never quite make out what it was saying. One thing was clear though - the message behind the voices. From a very young age Sam understood he was being watched and one day, when the time was right, the dark would be coming for him. Some nights the whispering filled him with such terror he would lay awake until dawn, not daring to close his tear-filled eyes, holding on so tightly to the scream caught in his throat that his voice would be hoarse the next day.

In retrospect he realized there had been only one thing standing between himself and complete insanity before the age of ten. It was the one thing that he could always count on, even when he sometimes foolishly didn't – and that, of course, was Dean. Whenever he could Sam would sneak into his brother's bed and hide there from the dark. The warm solidity of Dean's back against his was like a protective wall, a fortress nothing bad could penetrate. Sam would huddle against his brother utterly convinced that only in Dean's shadow would he be safe. The beat of Dean's heart drowned out the whispering voices, and the steady rise and fall of his breath would eventually lull Sam to sleep more effectively than any mother's lullaby.

As he grew older his fears gradually diminished. He began to ignore the whispers, and mentally blocked out the feeling that he was being watched, dismissing it as childish fantasy. The dark was just the dark, a lack of light, and the only things lurking in it were things he had been taught how to kill. There was everything, and yet nothing to be afraid of. If something came out of the dark after him he'd just stick a knife in it.

Then, in the fall of 2005, something changed. One night as he lay in bed, listening to the beautiful girl lying next to him sigh softly in her sleep, the dark started to whisper again. For the first time since he was a kid, Sam felt the terror creep into him. Several nights in a row he found himself unable to sleep, tossing and turning in nervous anticipation of something he couldn't quite name, and when he finally succumbed from sheer exhaustion, he dreamed.

Blood. Fire. Death.

The darkness was coming for him.

He'd been relieved when what did show up out of the dark was just his idiot brother - but of course, that had been only the beginning.

If only I'd known then what I know now, if only I'd told Dean to hit the road by himself that night….

Sam opened his eyes.

That was a fruitless line of thought. The darkness would have gotten him anyway, and perhaps with far more dire consequences.

A streak of light lay angled across the room, filtering through a window so caked with dirt it was close to being opaque. Captured within the light, tiny dust motes swirled and danced like daytime fireflies sparkling in the sun. The musty smell of said dust mingled with the sharper, unmistakable scent of bacon, while birdsong heard just outside the window clashed against the sound of a man whistling a barely recognizable version of Bad Company's "Bad Company."

These days Sam knew what – or rather, who – had been whispering to him in the dark. He was finally able to put a name to that which terrified him as a child. Ironically the opposite of darkness - Light Bearerer, Morning Star...

Lucifer.

"You belong to me, Sammy. You were mine from the moment you were conceived, and you will always be mine."

He let out a trembling breath as he sat up in bed. He smelled bacon, not the stench of rotting flesh, not the sickening tang of burning hair. The off-key whistling wasn't in the voice that had been torturing him nonstop for the past week, but in his brother's voice. They were at the cabin in Whitefish. Dean was in the kitchen making breakfast.

Stiffly, Sam got up and made his way to the bathroom where he pissed for what felt like an hour before shuffling out to the kitchen to sit down at the table with a yawn. He'd caught a glimpse of himself in the mirror and had been startled by the unkempt, bearded man staring back at him. He was still fully clothed save for his shoes. Dean must have literally just hauled him in from the car and dumped him in bed. Sam remembered none of it. He had gone out like a light only seconds after they'd taken to the road – and, thank God, he'd stayed out.

"I was getting bored," Dean said, with almost a guilty tone. He put a plate of bacon with scrambled eggs and toast down in front of Sam. A steaming cup of coffee was already in place. "I figured you might be hungry, and what man can resist the smell of bacon, huh? Tell me that."

Sam told him nothing, wolfishly devouring the food. When he finally spoke it was around a mouthful of egg. "How long have I been asleep?"

"Three days."

"I could go for more."

"I'll bet you could," Dean replied quietly.

Sam continued eating, gradually slowing down as his plate emptied. He asked for, and received, a good helping of seconds which he ate at a more respectable pace. "I don't like it."

Dean scowled. "You're eating it."

"Not the food," Sam paused, fork hovering. "You threw Cas to the wolves, Dean. How could you let him…."

"No." Dean cut him off abruptly. "We are not having this discussion."

"Dean…."

"I said no, Sam. Cas did what he had to do to fix what he screwed up in the first place." Dean stood up, taking his own empty plate over to the sink. He took his coffee too, but for a refill, and it hadn't escaped Sam's notice that there was more than just coffee in Dean's cup. "And he's safe. The end."

"You have no idea how wrong you are."

Dean's back went rigid, every muscle tightening as if he were on the verge of turning around and lobbing a knife at Sam's head. But then, with a deep sigh, he let it all go, his head bowing to his chest, his clenched fists opening. Sam was startled to see his hands were shaking. His words were barely audible, his tone that of a man weary to the bone – and not from lack of sleep.

"Don't tell me that. Please don't tell me that."

"We left him holding Lucifer's bag, Dean. We left him with Meg."

"He doesn't need sleep, Sam. He can handle it."

Sam's appetite suddenly fled. He dropped his fork on the plate with a clink – a sound that made Dean flinch. "That's not the point."

"Then what is the point?" Dean turned around. "It was killing you, Sammy!"

Sam looked him in the eye and without hesitation replied, "It still is."

"What?"

The pain in his brother's voice was palpable. Sam looked away from him. He wasn't sure how to make Dean understand – he wasn't exactly sure what Cas had done in the first place. It was as if the angel had left a little part of himself inside Sam's head, an angelic crossing guard diverting Lucifer away from Sam's consciousness. But Cas hadn't fixed the dam, he'd just stuck his finger in one particular leak – while everything else continued to gush out from gaping holes all around him. Hell was still nipping at Sam's heels. It just wasn't keeping him awake anymore.

"The point is," Sam said, avoiding the real question. "Just because he doesn't physically need to sleep doesn't mean Lucifer isn't going to drive him bonkers." He snorted softly. "Trust me on that."

"He'll be fine…"

"Dean, Cas might be the one thing on earth with even the slightest chance of taking on the Leviathan, and we've crippled him – if not killed him!"

"No." Dean shook his head, and rejoined Sam at the table. "Sam, he was already crippled, crippled with guilt. I'm telling you, as weird as it sounds, being locked in the nuthouse with Lucifer is probably the best thing for him right now. He feels like he deserves to be tortured, so let's just let him go through his whole mea culpa thing for a while and be grateful we've got him back at all."

Sam studied his brother's face carefully. "Is it all him, or is it you too?"

"What the hell is that supposed to mean?"

"Sure, Cas feels guilty. He feels like he should be punished, but you're in total agreement, am I right?"

Dean set his cup down. "And you aren't?"

"We're not talking about me."

"It's all about you, Sam! He nearly killed you, and he did it because he wanted to get at me. He didn't just betray us, Sam, he…."

Sam prompted, "He what, Dean?"

"Nothing, never mind." After a pause, however, Dean hesitantly added, "He brought you back from Hell, or so he said - I'm not sure I believe him – but he only brought back that soulless - thing." He paused again, his brow furrowing. "Sam, it's not the same…."

"He didn't go hands-on with my soul," Sam said softly, putting an end to his brother's awkward search for an explanation he didn't want to give in the first place, "like he did with you."

"He knew me, Sammy. I mean he knew me!" There was the slightest of wavers in Dean's voice. "How can I ever forgive what he did?"

How indeed, Sam thought reflectively. Even putting aside the basic fact that they were family, the whole reason Dean had gone to Hell in the first place was to save Sam. Castiel had laid hands upon the very soul Dean had given up in exchange for Sam's life, a soul that had been on the very brink of losing every last trace of its humanity as a result. Cas knew more than anyone else possibly could just how much Dean valued his brother, how much it had really cost him to bring Sam back. In Dean's eyes, using Sam's life as leverage had been the penultimate betrayal by one who was perhaps closer to him than even Sam himself.

"What about Meg?" Sam said finally. "Punished, maybe, but I know you don't want him dead, Dean."

At this, Dean actually seemed to perk up. "You know, Sammy, I don't think we have to worry about Meg and Cas. I honestly believe she has a thing for him."

"She's a demon."

"A sexually frustrated demon."

"Come on!"

"Hey, I call it the way I see it." Dean raised his coffee mug and sipped at its contents, winking at Sam over the rim. "I think some of you might have rubbed off on her during that possession."

Sam leaned back in his chair. "So I'm sexually frustrated with a hard-on for Cas?" he asked wryly.

Dean chuckled. "Are you? No, I mean she just seems more – negotiable – I guess - I don't know."

"She has a lot of good blood on her hands. Ellen, Jo…."

"Sam, don't." Dean's brief moment of good humor dissolved. "I know what she's done."

"If anything, she rubbed off on me, Dean – meaning I know her well enough not to trust her with anything or anybody. Castiel is her ace in the hole. She just doesn't know what to do with him yet."

"And neither do we, so for now, we wait."

They stared at each other, Dean's gaze a challenge. He was going to stand his ground.

With a shrug, Sam pushed himself away from the table and stood up. Even with a good dose of Castiel's healing mojo and some quality sleep, he was too tired to pursue the discussion any further. "Fine, whatever - I'm going to go get cleaned up. I smell like a Yeti."

"With that rug on your face you look like one too," Dean replied dismissively. He flipped open his laptop and Sam left the room feeling privileged not to know if it was the latest on Dick Roman or his most recent porn fetish that his brother sought.

Sam showered, washing away an odd combination of hospital smells that still clung to him – clinical strength disinfectant, and the stink of sweat laced with both fear and the "aftertaste" of all the sedatives they had pumped into him. A razor gradually revealed a more familiar face beneath a week's growth of beard. It was still rather pale, and gaunt, but less….

"Haunted," Sam murmured, zipping up his kit. He looked back up at the mirror, and froze. "No...you...you can't be..."

Lucifer stood behind him, watching him in the mirror. He said nothing, but simply smiled and reached out a hand to touch Sam's shoulder.

Sam clamped his teeth down to hold back a scream. Agonizing pain shot through his body, causing his hands to grip spasmodically at the sides of the cold porcelain sink and his knees to buckle. It wasn't the flames this time. This time it was shattered bones, over 200 in all, each methodically smashed one, by one, by one. In the mirror he could see his face beginning to swell into something unrecognizable - a bag of pulverized flesh and broken bone. Blood ran freely from what had once been a nose, and from a slack mouth full of broken teeth within a shattered jaw.

Sam's muscles went limp. He went down to his knees and then collapsed onto the floor unconscious. He woke barely a minute later, shivering with cold not entirely due to his state of semi-undress. Unable to make himself get up, he closed his eyes again. He could sense Lucifer standing over him, smirking silently.

Mute, but not gone, never gone.

"I'm sorry, Sam. I'm so, so, sorry…"

Castiel's presence was distant, barely a tickle against his mind, but there none-the-less, keeping Lucifer from doing more, from driving him insane until death. As a small child Sam had clung to Dean in the dark. Now he reached for the light and warmth of the angel's essence left inside him, clutching it like a weapon to beat back the darkness. It eased his pain, and gradually his shivering subsided. Lucifer flickered once, twice, and was gone.

Sam held tightly to this new talisman, realizing that, like his scarred hand, its effect might not last. None of it might last. What would happen when it came time for Castiel to give back what he'd taken, when Lucifer's gag came off again? It was a thought upon which Sam couldn't bring himself to contemplate; at least not now. The slow destruction of his sleepless mind, the agonizing creep of death overcoming his physical body - those memories were too fresh. He couldn't bear to have it all return, the very idea terrified him. He'd put a gun to his head before he had to go through that again so soon. Castiel had taken on the burden. Let him keep it.

Dean had no real idea how badly the angel was suffering by taking just a modicum of Sam's torment onto himself, but like Dean, Sam was unable to stop feeling like it was only just desserts.

I did my time. I paid the price for letting him out.

Cas had brought back a soulless Sam, a cold, unfeeling killer. He had opened Purgatory, smote hundreds of people, and freed the Leviathan. Castiel's body count was rising daily. It would, albeit indirectly and over time, top that of Lucifer's truncated Apocalypse.

"And don't forget," Castiel whispered, with a touch of sad wryness. "I betrayed my only friends."

Sam slowly levered himself to his feet. In the mirror he saw only himself, whole, but still obviously exhausted and, if truth be told, frightened.

"It's all right, Sam. I'm going to make it all right, I promise."

A knock on the bathroom door startled him. The angelic hotline disconnected and although Sam could still feel him, Castiel's voice was gone. Dean's voice came muffled through the door. Sam had been in the bathroom too long. His brother had become worried.

"Sam? You okay?"

Sam opened the door. "I'm fine." And he suddenly realized it was not a lie. He was fine, and with a little faith, he might just be able to stay that way.

Dean looked slightly skeptical, but then shrugged it off. "If you're done, get out. I gotta pee." He jerked his head back over his shoulder as he shoved past Sam into the bathroom. "Get dressed and check out the news of the weird. I think there may be a job down in Arkansas." He paused before shutting the door. "Do you think you're up to it?"

Sam gave him a wry grin. "I'm as ready as I'll ever be."

"Good."

Sam's grin faded as Dean disappeared behind the door. He dressed, and sat down at the computer to read whatever story had attracted his brother's attention. It was back to business as usual.

The whispers in the dark were silent once again, and Sam could dare to dream.