If I can't have you as my vessel, I'll tear your life apart instead, shred by shred until there's nothing left but the strings of your sanity and an empty, broken shell.

Sam knew that Lucifer wasn't the type to screw around.

But he hadn't known how seriously he'd meant the threat, either.

Sam could taste blood. The copper-and-iron taste still clung to his senses, even after he'd stopped biting his tongue, even after he'd shakily swallowed, trying to dilute the sharp taste.

"This is what you get, Sam." The Devil would say, softly, looking down at his bruised and battered vessel that he said over and over again – over and over – he didn't actually want to hurt. "This is your punishment."

Still, Sam would stay silent. No sense in crying out, in pleading, in begging, in bargaining, when it only encouraged him, only gave him satisfaction, only made things that much worse.

Dean didn't know, yet, that his 'hallucinations' had taken a turn like this. Sam hadn't told him. It wasn't like he'd be able to help, anyway, despite however vehemently his brother insisted otherwise. And that was just it – Dean couldn't help, so Sam didn't want to burden him with horrible, painful knowledge that he couldn't even do anything about. Dean would be better off not knowing.

But the pain wasn't even unprecedented, anyway. It was dizzying, it was agonizing, it made him want to scream his lungs hoarse, but he'd had worse. Before it'd been in smaller doses, but it was okay, it was okay, he'd get through it, it'd be over one day – "You belong to me forever." Lucifer kindly corrected, tracing a fingernail down the front of his throat and digging, drawing blood – it'd be over one day because it wasn't real – "I'm very real, Sam." The Morning Star assured him.

This time Sam did scream himself hoarse.

Lucifer was always thorough. Sam always returned to Dean healed, no marks on his body, no blood or bruises or scratches or telltale signs of any sort on a single visible inch of him (he'd snuck away from Dean in the first place with the excuse that he needed space, he needed time, he'd be fine in a little while but he needed a break now and then to recuperate from the years he'd spent in the cage).

Dean had understood.

Dean didn't understand at all.

Only in his heart and mind did the scars and the pain remain, festering and bleeding, aching, dragging him further down every day into an dizzying, draining hollowness he couldn't explain. True to his word, Lucifer was hollowing him from the inside out. Ripping down his resistance. Whittling away at his will. Bastardizing his belief.

Breaking him.

It's not real, he swore to himself every day, his grip on the porcelain sink tight to the point of bruising as he stared at himself, desperately, in the mirror. It isn't. Because it couldn't be. But sometimes, and more and more frequently as Lucifer's punishments wore on, he found himself questioning that.

"I'm very real, Sam." A bodiless murmur in his ear would promise him. Sam would flinch away involuntarily, straighten back up, and then pretend nothing had happened at all (because he needed to pretend. He was going to lose his mind if he acknowledged Lucifer any more than he already did outside of their torture sessions.)

He would ignore the amused chuckles coming from somewhere he couldn't quite pinpoint as he made his way out, too. He would ignore those too.

The thing that was the worst, in Sam's opinion, was this: he could hide his moments of weakness from everyone else. But Lucifer was there perpetually; constantly; inside Sam's head at all times day or night whether he could feel him there or not. Lucifer, even better than himself, knew every one of his weaknesses. And he used them against him.

Constantly.

And the first time Lucifer had crossed that final line, burned that final bridge, taken that final step and violated Sam in the last possible way he was capable of violating him, all Sam could think was, why hadn't he seen this coming. He should have seen it coming. How had he not? He was sure, at some point, he had predicted it, actually, and had just shoved it down, down, as far as he could, instead of thinking about it, instead of dealing with what would have been, at that point, a completely imaginary mind-strung situation born of fear.

The first time Lucifer had crossed that final line, and stolen Sam's last shred of bodily autonomy along with it, the world hadn't ended with a bang, or a whoosh, but a whimper, and a dry sob, echoing lightly off the stone floor slick with his blood.

Sam had curled in on himself and struggled to breathe, in so much pain in a place he had no experience being in this much pain in that he wondered how he could still exist, how he wasn't dead from it. But, no – dying would be too easy, wouldn't it? Lucifer wanted him to suffer. Lucifer wouldn't let him die, because in death there was respite and peace and touches that didn't burn and freeze and drag like nails all at the same time. Death was too easy.

"Exactly," Lucifer murmured, carding gentle fingers through his hair, and Sam couldn't muster the strength to pull away as silent tears slid down his face.

Lucifer hadn't healed him that time, either. He'd healed the bruises and lacerations and broken rib, of course, just fine. But it burned and ached to walk, and took an enormous amount of effort to stifle his pain in front of Dean, and it was a constant, constant reminder of something that he had never asked for or consented to.

But then again, that just about summed up his relationship with Satan, didn't it?

True to his word, Lucifer was hollowing him from the inside out. Ripping down his belief. Whittling away at his resistance. Bastardizing his will.

Tearing him apart.

It wasn't real. It wasn't real, Sam had thought, after a week of the same, feeling almost deranged, blinking back the wetness in his eyes as he stared into the grimy mirror, trying to regulate his breathing and still his trembling hands. It wasn't real. It wasn't real. He took a sharp, shuddering breath. Even his lungs hurt, now, and he wasn't sure how much of that had to do with Lucifer and how much had to do with his own crumbling will.

It wasn't real. But he wasn't sure how much more of this he could take.

Lucifer crooned approvingly in his ear. Sam shuddered; silently prayed for Dean. For an escape. For anything except the bad, broken thing his life had become. Still, Lucifer crooned and shifted closer, and this time? This time he didn't bother to pull away.