This is set the night and morning after 5.14. It's gen. There's gore and man pain and evil superpowers.
Stolen from Kripke, with compliments.

The blood was screwing with him. It was smart, vindictive: when he'd just been between doses, rationing it out, or that time Ruby had let him starve until he broke—those times it'd been normal stuff. Sweats, chills, insomnia, aches, mood swings, just like any regular heroin addiction. But when he stopped—when it knew he wasn't going to go out and get more—then it got mean.

Sam is the epicenter of every trauma on the Continental US. Mommy didn't love him. Daddy didn't love him. Each of Lilith's dead hosts—four elementary school girls and the dental hygienist—came by to say hi. There was a scene change and he was off the bed, on his feet, sprinting through a vine-infested swamp that looked like the soundstage for Dagoba, fleeing from Dean, who grinned the dead-eyed grin that Sam hated, until Sam tripped on a vine and impaled his chest and his face on a concealed pit trap. Dean caught up to him, hauled the hidden bed of spikes out of the scum-green water, and stretched Sam's arms and legs between a pair of bent saplings, singing "Mr. Brownstone" as he threaded ropes through stab wounds in his limbs, and Sam groaned around the stakes in his body and wondered how he wasn't dead until he caught scent of his own blood and went mad with hunger.

Then he'd be alone on the bed in the panic room, and it would be shakes and thirst again. Hazily, he knew he was hallucinating. But in the intervals between, when the blood wanted him to meet somebody, he would feel utterly lucid.

Like now. But now he was alone, in the dark iron pit like a bottle, blinking up at the spinning fan blades as they caught the edge of a porch-light's glow against the fathomless black sky. Waiting.

The bed shuddered under him and he jerked against the cuffs, pulse speeding.

Most of the time, he forgot about the telekinesis. It wasn't the fun part, wasn't efficient. It couldn't kill Lilith. But it was enough to roll a steel camp bed with him on it.

"Dean!" he yelled, hoarse like he'd been screaming all night, as he struggled to sit up and clutched the rails as the bed tilted. The chains jerked his ankles tight. "Stop. Stop, stop, stop." The power ignored him, lifting the head of the cot painfully slowly as Sam riffled through all the raw spots in his brain, trying to channel it somewhere else—exorcise his leg, fry the goddamn fan, hold his ground—but the blood had something planned, even if it was just to slam Sam's face against the concrete until it killed him.

A force pinned him to the bed so hard the springs squealed. "Dean!"

The bed trembled, then shot down, the head rail striking with a deafening clang, flinging Sam down like a wasp caught against a flyswatter.

He didn't hit. He panted in the dark, feeling his own breath blowing up against his face from the hard floor inches away, still squashed against the mattress with all of Jupiter's gravity.

The blood slowly, gently lowered him to the floor, and the bed squealed again and collapsed on top of him. Under the musty cotton mattress, arms and legs still cuffed to the bed frame, Sam tried to struggle, to turn his head so he could breathe, but his entire body went pins-and-needles and fell limp.

Paralysis. That was new.

The window on the iron door creaked open and a flashlight beam poked through, yellow light glancing against the floor. He heard Dean curse and slam open the latch.

Dean was here.

Dean wouldn't bring blood, Sam thought like the savage pathetic vampire he was, but if Dean was still here, maybe Dean wasn't going to ditch him so he and Castiel could find some other way to kill the Devil, alone. Maybe goodbye was going to be face-to-face with the knife instead of leaving Sam for some other hunters to track down.

Maybe goodbye was now. Sam's vision flared red. Maybe goodbye was now, and the goddamn blood was making him play dead for it. He tried to struggle, to move, blink, something, only managing to send flares of cold fire through his limbs.

Boots scuffed against the concrete and the flashlight clattered to the floor, the beam blinding him. The bed jostled on top of him and the headboard clattered away, then Dean's fingers shoved at his limp left arm, pushing it under the bed, and the cuff on Sam's right wrist began to bite into him as the bed frame rolled up. His shoulder blade slid almost off his chest from the pull of his own weight, and his head dangled dizzily from his limp neck where nerves and bones ground together.

Dean grunted. The mattress began to flop back into its original position against the bedframe, and Sam followed, the pull of the cuffs easing until the frame clunked to the floor. Dean's rough fingers jabbed at his throat where Sam's pulse was leaping. Sam tried to move again and burned for it. He just wanted to say goodbye.

Dean made a relieved puff of breath and took his fingers away to tug Sam and the mattress back into place on the center of the frame. "Sammy," Dean sighed, low, rough. "What'd you do to yourself this time?"

It's not the blood that's the problem, I need it I need it and see what happens when I don't get what I need? some corner of his mind was snarling. It was a big corner.

Dean got the flashlight and checked his scalp over, running his fingers through his hair and gripping him by the temples to turn his head this way and that. He caught a glimpse of Dean's blurred face, looking worn-down and aged in the yellow light, before the flashlight glared painfully into his eyes. First one, then the other. Blackness and stars exploded in its wake. Dean slapped him on the shoulder and moved away, taking the light with him.

No, Sam thought, stop, stop, stop, not now, and rage surged in him as he strained to just make a sound, because his last moment with Dean was not going to be like this. Nothing he could say could make this right, because he was a monster and he'd broken and re-broken everything they stood for since Dean had called him back, but he had to be there, he had to say something. The blood burned him, laughed at him.

There was a scrape of steel on concrete, and bootsteps returning. The bed tipped up again, and steel clattered and scraped together under his ears. Dean had put the headboard back. The boots and the light went away again, until Dean returned with the footboard, reassembled the bed, and gave it a shake to check its stability that sent the springs squeaking and Sam's tongue lolling against his slack-open teeth. "Hose clamps," Dean muttered. The mattress at Sam's knees dipped with a warm weight and the flashlight flicked off.

Sam listened to the soft huffs of Dean's breath over the throb of the fan.

"I don't know what I'm doing," Dean said.

Sam was eavesdropping. The blood was making him eavesdrop on Dean's thoughts and he couldn't stop, and since it was the blood doing it, Sam wasn't going to like what he found out.

"I know," Dean ground out to the dark, "I know what I gotta do. Dad told me. You told me. Wasn't that complicated, but you know me, I always screw everything up." Dean's warm hand rested on Sam's bare ankle. Twisted his foot back and forth. Left. "Just—can't—" Dean croaked. He swallowed loudly. "Know it's not right, not supposed to let you be…this. S'posed to watch out for you. But like you said. I'm weak. Spent all my time taking care of you and now I don't know how to do anything else."

Sam's body took a slow, involuntary breath as he burned in his prison, struggling to get out. The fan hummed and Dean toyed with the limp fingers of his right hand. Dean's weight left the bed abruptly and the springs bounced, squeak-squeak, up and down. Fingers pushed the hair out of his face.

"Love you, Sammy," Dean murmured. "But I wish to God I didn't."

Bootsteps toward the door, the shriek and clang of the latch, the hum of the fan, and another maddening involuntary breath.

And then it was Lilith standing over him in a spot of moonlight, Dean pinned bleeding to the wall like a clothed crucifix, and a thing like a dog but not a dog—skinned with hair springing up from glistening muscle, eye sockets filled with fog that dribbled and drifted with each eager twitch of its heavy head, knives bolted into its bleeding jaws in place of teeth—with a clear plastic tube fixed with white medical tape into its heaving throat, that Lilith held teasingly over his face, kinked shut.

Sam surged upward against the cuffs and the little girl jerked it out of reach.

"Sam! No!" Dean bellowed, and Lilith tossed her host's blonde curls in annoyance. Sam heard ribs cracking.

Lilith dribbled a little black blood from the tube into her palm and waved it up and down. Sam's eyes tracked it, his nostrils flared, his neck and shoulders tensed with the effort of holding himself off the bed. Her hand darted at him and he followed, teeth snapping, but she was too quick for him, smearing blood on his forehead before he could reach her tiny hand. The blood tingled and burned against his skin and he gasped, tensing off the bed.

"You like that, Sammy?" Lilith cooed. "It's extra Hell. Like extra sprinkles!"

Sam panted, lunging against the cuffs at the hellhound, at the catheter.

Dimly, he heard Dean groan.

"There's no coming back from this, Sammy," Lilith whispered, in that loud breathy way little kids had. "Just one taste and you're mine forever. You want it?"

Sam was salivating so hard his cheeks ached. He nodded frantically. Dean was on the wall moaning, "no, no, no," but the blood was on his face and he could smell it and feel it. He was beyond reach.

"Say please," Lilith scolded.

Sam's lips worked. He had to swallow before he could talk. "Please," he whispered. "Please, please, please-please-please-please—"

"Say pretty please."

"Please—pretty, pretty please, pretty-please—"

"Good boy," said Lilith, letting him seize the tube with his teeth. Sam's mouth burned with brimstone as he sucked it down.

But it wasn't real. It wasn't real, and the rage pulsed in him until he bellowed with it, jerking and kicking at the bed.

Eventually, Sam slept. When he woke, his arm was asleep, pulled awkwardly by the cuff, and he was starving and thirsty and shivering and he itched all over. It was almost noon, and the sun had crept across the floor into his eyes.

He hoped someone was coming to get him.

He lurched up with a jerk that had him dizzy and nauseous. The bed. The bed was off-center, like it would be if he'd TKed himself upside down and Dean had come in to reassemble it. Maybe Dean was still around. Maybe Dean was coming back because Sam was a toxic anchor on his spirit.

He tugged against the cuffs and felt the junction of the headboard and the bed frame. Hose clamps. Dean had said something about hose clamps—maybe he'd come back while Sam was out of it and screwed some on to keep the bed from coming apart again. He felt the steel tape—it was smooth, new. He swallowed and rolled back onto the bed.

He felt normal. Horrible, filthy, damp, but normal. The fan hummed the seconds like an overloud clock and he wanted to shoot it. He was going to be hearing the ghost of that noise for weeks. His head throbbed with the beat of the fan and he sank into a light daze of pain, anxiety, and boredom.

The sun and the shadow of the fan crept across his face as an hour passed. Two.

"He is," echoed Castiel's harsh voice from the hall outside. Sam roused, squinting against the sun, and watched the door from the corner of his eye. The window creaked open, then the latch. Dean came into the room, wearing the same clothes as Sam had seen him in that night, the same weariness.

The pit of nausea in his stomach tensed harder.

"Hey," said Dean, leaning over him.

Sam coughed and tasted blood. Too much yelling. "Hey," he whispered.

"You ready to get out of here?" Dean asked, producing a key.

Sam nodded heavily. Dean freed his arms and his legs, checked the scrapes and bruises Sam had put on himself, and put an arm around his chest as he wobbled to his feet.

"Dude, you reek," Dean murmured.

"Sorry," Sam breathed, half his weight flopping sideways and his feet tangling. He ignored the dance of the hallway around them and watched the ground as they headed for the elevator, step by step.

In the shower, Sam lowered himself cautiously to the floor and stayed there until the hot water ran out. Then he dressed, leaning against the wall, glanced at his hollow, bloodshot eyes in the mirror, and crept into the kitchen.

Castiel was stirring a pot of canned chicken soup with a wooden spoon in precise clockwise strokes. It reminded Sam of the fan.

"You're still here," said Sam stupidly, gripping the top of the refrigerator for balance.

"Yes," declared Castiel.

Sam waited for more, but more was not forthcoming. He pushed off the refrigerator and coasted to the nearest kitchen chair. "Can, uh, can I have some soup?"

"Yes," said Castiel again. He picked up a bowl and a spoon that sat next to the empty can and set them on the table, and filled the bowl with half the contents of the pot. He put the pot back on the stove and continued stirring.

Sam sat and watched dust dance on a sunbeam as the soup steamed. "Where's Dean?" he asked softly.

"Dean is with Bobby Singer," replied Castiel. He had not once looked at Sam, and did not now. "He asked me to feed you and to tell him when you wish to speak with him."

Sam nodded and looked out the window at the cold clear sky, wishing he could see the car. See how many duffel bags were in the car.

"He also said to tell you that he's not going anywhere and neither are you," Castiel informed him.

Sam shivered and wrapped his hands around the hot bowl. He was hungry and sick at the same time and it hurt to swallow, so he just hung his head over the steam and breathed it in. Dean wasn't leaving him. Dean hadn't shot him, not that it would do any good with the vessel thing hanging over their heads. But that left what Sam had heard Dean say last night. The visit that could have been real.

"Did Dean ever come in?" Sam asked, watching the angel by the window, an icon in a sloppy loose-fitting trench coat, tirelessly stirring.

"No," Castiel said. He glanced at Sam, hawk-like, and Sam flinched. "You had several telekinetic episodes. It would have been dangerous for Dean to enter the room."

Castiel's gaze swung back to the window and Sam took a slow breath of steam and chicken with rice. Dean hadn't been there. That wasn't Dean, standing there defeated and helpless and poisoned by Sam's presence.

It was just another horrible nightmare.

Sam gasped and his face warmed; he shot up from the table so fast the soup spilled. "Sam," said Castiel, dropping the spoon and gliding to Sam's shoulder. Sam waved him off, breathing slow and deep.

"I'm good," he choked, staggering from the kitchen. "Good. Just…stay." He collided with a wall and shouldered himself off of it, blundered toward the nearest door, the cobweb-infested linen closet, and shut himself in. He sank to the floor and buried his face in his elbow as he shook with gasp after gasp, great heaving shudders of relief that had him sobbing like a six-year-old coming down off a tantrum. That was what addicts did, right? Addicts had humiliating messy weeping breakdowns, and he was damn lucky he'd made it to the closet for his. He clenched his teeth and squeezed his eyes shut in the dark, quashing his breath down to a soft rasp. His bare feet scuffled in the dust.

He wasn't a vampire anymore. He'd slipped, and he'd gone under, and Dean was still out there with Bobby, waiting for him, just like Sam used to know he would.

The rift was over.

Five minutes later, he wiped his face off on his shirt, dusted the lint from the closet off of his pants, drank his lukewarm soup, and followed Castiel out of the house to Dean.

-

Between My Bloody Valentine and Dead Men Don't Wear Plaid, Sam seems to have had an abrubt personality reboot. In Meat Swap, we have now-familiar Angry Sam mixing his bizarre health shake like he's going to kill something with it. In Dead Men Don't Wear Plaid, Sam is once again the mercy to Dean's jungle law, and he's asking if Bobby is going to be okay.

We're seeing Vintage Sammy again, and correct me if I'm wrong, but we haven't seen him since mid-season 3. We've had Sam-on-the-end-of-his-rope, Sam on 'Roids, and Self-Sufficient Hunting Partner Sam, but by 5.15, 5.16, and 5.17, it's like Sam sproinged back into his original shape. He's not wearing the rhinoceros hide anymore. He's not putting out those give-me-an-excuse-to-strangle-you-against-the-nearest-wall vibes and scaring small children. The radical difference between the way he's acting lately and the way he'd been acting from Season 4 to 5.14 demonstrates just how abnormal those behaviors were.

Apparently, losing it in My Bloody Valentine was a major healing event for Sam. The way I figure, Sam had assumed that his continued partnership with Dean was only a partnership, and was contingent on his good behavior. He was constantly waiting for Dean to call it off, never letting himself relax in case he had to go it alone again.

Now, after Sam's blown it worse than he ever had, to the tune of two, three gallons and two dead hosts, Dean is still there. Sam finally lets down his guard.

Now Sam gets to be the sort-of-sane one and Dean gets to go all angsty and stupid.