THEN

Sam uncurled his fist. The muscles in his arm bunched as he bit back the stress and the torment and the overall pain of the past three months. Ruby was watching him from across the motel table where she sat cleaning her knife, eyes cautious. He knew what she would do, that when she saw he was upset she'd take his hand, pull him back onto the bed, offer up her blood or her comfort. Sam didn't want to think about what Dean would say if he knew about Ruby "comforting" him.

Actually, he didn't want to think about Dean at all. It was enough to wake up every morning reliving his brother's screams as the hellhounds ripped into him, to see the emptiness in Dean's dead eyes every time he closed his own. Hunting with Ruby had proved an adequate distraction, but he needed to be distracted again now. He needed another lesson, and he had an idea of what he wanted to learn.

"Ruby?" he said, coughing when he realized how brittle his voice sounded. "I've been thinking."

"That's dangerous," she said with a smirk, but she set the knife down on the table to look at him in the eyes. "What about?"

"Well," he said, thinking back to Lilith's white eyes looking out of Ruby's meatsuit, and further back, to the feel of Meg moving around inside him. "Possession."

"Oh." She looked acutely surprised, but she was trying to hide it. Then- "Wait, you're not gonna throw a fit about coma girl, are you?" she said, gesturing to her body.

"No, no," said Sam, shaking his head. "It's just…" He bit his lip, deliberating. "One time, Yellow Eyes was possessing my dad and he… got free. Took control." Ruby watched him closely. "I was wondering… if that were something that I could learn."

"You want me to teach you how to overcome possession?" said Ruby, her eyebrow arching. "Seriously, Sammy?"

"It's Sam."

"Sam," said Ruby. "You're crazy."

"Probably," he said, and he felt it too. Hell, anyone could take a look at his life and get a feel for just how insane he must be. Outside of the fact that he hunted ghosts for a living, he was also working with- sleeping with- a demon, drinking himself to despair, and refusing to give his only brother the funeral he deserved. It was all a mess. He sighed. "Probably, yeah, but I still want to do this."

And Ruby, well, Ruby usually came around in the end when it came to what Sam really wanted, and so it happened that an hour later she was lying on the bed- to ensure that her meatsuit wouldn't topple over when she stopped inhabiting it- and Sam was standing in the middle of the motel room, looking tense but stubbornly fixed on figuring this out.

He'd nicked a small cut into the tattoo on his chest so that it wouldn't block Ruby, and now he steadied himself against the dirty floor, trying to get ready. "I'm going to regret this," he muttered. Looking up at him from the bed, Ruby smiled.

"You probably will. I've heard from several reliable sources that this isn't very fun at all." She settled her head back down on the bed and spoke to him. "Alright, if you can't fight me off in five minutes, I'll hop out and you can take a breather before we try again."

"And you won't…" Sam lingered on his fear in this experiment, that she would turn on him, mock him for ridiculously letting her possess him by rampaging across the city wearing him like a suit. She seemed to understand what he wasn't saying.

"Please," she said, and even though she wasn't looking at him he could hear the smirk in her voice. "What do you take me for?"

In one fluid movement of black smoke, Sam wasn't Sam anymore, he was trapped inside, pushed to the very edges of himself while Ruby looked out. She flexed his hands, craned his long neck around, meeting no resistance. "Alright, Sam," she said, Sam's voice echoing in the empty room. "Give it your best shot."

He was clawing at her, his mind pummeling against hers, but there was no effect. She hadn't expected him to be able to take control, and he didn't. Five minutes later Ruby was back on the bed and Sam was himself again, panting in the middle of the motel room.

"First try," she said. "You'll do better next time."

He didn't. Five times she possessed him, and every time, no matter how hard he threw himself against her voice in his head, no matter what he willed himself to do, Sam couldn't overcome Ruby's possession. Finally, as she stretched back into her usual body, she dropped a piece of advice. "You're doing it all wrong," she criticized. "You're throwing your mind at me, but I'm not controlling your mind. You're free to think whatever you want. It's not mind control, it's possession, and it isn't about thought it's about action."

He stared at her, feeling weak and exhausted, and like this had been a dead end terrible idea. "Then what do I do?" he said.

"I'm going to regret this," she sighed, echoing his earlier comment. "Try and move your fingers," she said. "Or your toes. Start small and work your way up."

"How do I do that?" he asked, looking down at his fingers now. When he was being possessed, they didn't feel like his own, but like gloves being worked by another owner.

Ruby pursed her lips, and he could tell she was wrestling with herself over whether to reveal any more. It had to be some kind of huge infraction to release hell's secrets, but given all she had already done, he assumed she didn't have a problem breaking more of the rules.

He was right. "You need a thought," she said. "And not like 'get out of me' or 'stop possessing me', just something that's going to make you strong. A really powerful thought."

"Any happy little thought?" he replied, a small smile twitching up the corner of his mouth. She just stared at him. "Peter Pan?"

"Who?"

"You know, the Disney movie?" Nothing. "Seven hundred years and you've never seen a Disney movie? Not Snow White, not Dumbo?"

"Dumbo?"

"Never mind." Discussing Disney movies with a demon. Sam shook his head and readied himself again. All he needed was a thought. A thought, and to move his fingers. "Okay. Try it again."

This time was different. When Ruby took control of him, he didn't waste any time thinking at her. Instead, he took a mental step back and felt for his hands, thinking it might be easier if he focused on one at a time. Just the right hand, okay. One step at a time. Now he needed the thought.

Sam had a lot of powerful thoughts and memories, most of them painful. He remembered Jess's death, being reunited with his father- only to lose him again, burying Dean. They were all too painted with pain and anger to work, though, and he knew he needed a happy thought. This proved fairly difficult, given the life he lived.

He did have one happy, recent enough memory, of singing Bon Jovi in the car with his brother. That day had ended terribly, but that one moment in the car had still happened, and despite everything, he had been happy.

With that in mind, "Wanted Dead or Alive" skipping through his head, Sam felt his right hand, the tips of his fingers, the flecks of blood or dirt under his thumbnail, the scar on one knuckle from a run-in with a ghoul. He felt it, he owned it, and he stretched out his palm, long fingers splayed.

He felt Ruby smile using his lips, and then she flared, fighting for control, testing him. He gripped his right hand into a fist, then relaxed it, working the muscles in that one hand as he worked his will up his arm, into his shoulder, to the rest of his body, and then despite Ruby's attempts to regain control, he was himself again.

"I did it," he said, mainly to prove to himself that he could talk with his own words and his own voice, and then Ruby coughed out of him and reoccupied the body on the bed.

"Good job, Sam," she said, breathless. She looked tired, which surprised him, and- though he must have been imagining it- a bit scared. She also looked somehow proud. "Good job, Sam."

NOW

When Jimmy Novak had said that being a vessel was like being chained to a comet, he hadn't been kidding.

Sam had died before, more than once. This was worse. This was every ounce of evil and suffering and hatred in the universe doubled and crammed inside of him, seeping through and sticking inside him, and for one merciful moment he thought it would be okay. He could hear himself responding to Dean, saying he could do it, standing up in front of the windy hole to hell. For one moment, he thought that maybe he really could do this, that he really was about to jump into the Cage.

But he was kidding himself, because those weren't his words. He hadn't actually said anything, or hadn't meant to- it was someone else talking. Lucifer stretched, and Sam's body moved, and that was when he realized he had already lost.

It's hilarious, Sammy, that you thought you could do this. The Devil was talking to him inside his head even as he taunted Dean. You couldn't even control yourself when you freed me, so what made you think you could control me? And then he's reliving every awful moment he'd even endured- Jess dying, Dean's deal running out, Dean calling him a bloodsucking freak. It was like the time he'd been locked in the panic room, hallucinating, but this was worse because it was all real.

He was really sticking the Horsemen's rings in his pocket, then really killing the group of people from his past, then really standing in the middle of a cemetery as the Devil marched around wearing him.

Sam tried to fight back, with everything he had, but Lucifer was drowning him in his own head. He felt trapped, suffocated by guilt and pain and anger, Lucifer pressing him into the edges of his skull until he thinned away to nothing.

There was Adam- Michael. He was Michael now, just as Sam was Lucifer. He wanted to keep fighting, had to, but there was no way Lucifer would give in now. It's the end of the world, you might as well enjoy it, Lucifer whispered as Sam screamed in his mind. Sam tried to recall what Ruby had told him- because even though she'd ended up a traitor, even though she'd been working for Lucifer and Lilith, it was all he had. He tried to find a thought strong enough to fight off the Devil, but he couldn't think, there was only the constant stream of Stop this let me out I hate this I hate this just let me die.

And then there was a sound, a sound he'd known all his life, a sound that could cut through the suffocating noise of Satan's taunts and torture. It was the engine of the Impala, cutting across Stull Cemetery. And then…

Def Leppard's "Rock of Ages". If there were any question about who was driving the Impala, it was gone now, and Sam wished more than ever before that he could take control. Not to stop the Devil, not even to open the Cage. He wanted to come back to himself only long enough to yell for Dean to leave, to go far away. He wanted to warn Dean about the torments that Lucifer had planned for him, wanted to get him away from the Devil, but he couldn't.

Because the Devil was still him, and he was still locked up inside himself, and the apocalypse was still happening.

Sam couldn't hear much, because while Lucifer was focusing on Castiel and Bobby, who'd just shown up, he was also holding Sam back, dousing him, deafening him, cutting him off from the world. He could still see, though, and what he saw made him want to gouge his eyes out. He saw his best friend exploding, and he saw his uncle's neck snap. He saw his own hands throwing Dean against the Impala, he saw Dean's mouth moving, but he could hear nothing.

It didn't matter, because he knew Dean, and he knew what Dean was saying. He would be telling off the Devil, back-talking Evil itself with sarcastic remarks and jibes. It was what Dean did, when he was scared, when he was angry, when he was trying to be brave. His snarky jokes would always be his weapon, and his last words would always be some kind of darkly funny jab at whoever was killing him.

Sam felt like a puppet, limp and worn out and he just wanted to die, just wanted to die before he had to feel himself killing Dean. Because Lucifer was going to kill Dean. Sam could feel it, sense the plan, and he knew that Dean knew it too, even as he lay panting across the car spitting out insults-

No.

Suddenly what Dean was saying cut through the deafness like a knife, and Sam realized he was wrong, because Dean wasn't talking to Lucifer. "It's okay," Dean was saying. "I'm here. I'm here. I'm not gonna leave you." Lucifer kept whipping him around, but it didn't matter, because Sam got it.

Dean wasn't giving up. Dean hadn't given up on him when he ran off with Ruby, and he wasn't giving up now.

Ruby.

All he needed was a thought.

The Impala gleamed in the sun, and Dean said again that he wasn't leaving, and Lucifer pulled back and suddenly Sam didn't need to rack his tormented brain for a powerful thought because suddenly he had a million of them, memories flooding through of eating and sleeping and laughing in that car, jamming out to Dean's mix-tapes and talking to Dean and saying goodbye to Dean and going after a Wendigo with Dean and Dean. He felt for his fingers.

Sam uncurled his fist.