Author's Notes: A possible explanation for why Sam is different. Also delves into what happened to Adam a bit. Dean protected Sam and Sam learned almost everything he knew from Dean, so really, he had no choice when it came to saving his little brother.

Author's Theory 2: The Winchester family is one that is prone to selling their souls to save those they love. Mary sold hers for John, John sold his for Dean, Dean sold his for Sam, so I think there's gonna be a variation on this pattern when we find out what's up with Sam. I think Sam sold his soul to an angel (since they can make deals now and Heaven and Hell seem to be competing to see who can get the most sould) for the life (or lives) of people he loves. Probably Dean, but maybe some others got thrown into the mix too.

Summary: Sam always looked up to Dean, even when it didn't seem like it. So of course he would follow in his brother's footsteps, follow his patterns. Even in this.

Cycles

"Sam, what's wrong with you?" Dean asked his shaking, pacing little brother once again. "You have to tell me. What's going on? What happened to you?"

"You have to go. You have to leave and take them and run."

Dean stared incredulously at Sam, anger boiling over.

"You- You're the one that brought me back into this. You showed up out of nowhere after a year and pulled me back in!"

"I know…but now, you know what's out there. You know everything new that's happening. You know enough now to protect them, protect yourself." Sam licked his lips and nodded to himself.

"You have to leave. Take Lisa and Ben and run someplace they'll never look for you. You'll have to become ghosts…but Dean-" Sam looked up at him and Dean finally, finally, saw some real emotion in his brother's face. "You'll be safe…This is all I can do for you now."

Dean scrubbed a hand over his face, the pure desperation in his sibling's eyes stole away the core of his anger. Sam smiled as best he could at Dean and dropped his head again.

"You have to Dean. Forget about hunting and monsters. Forget you ever had a brother…and run."

Dean breathed a moment, composing himself.

"Sam…what. Is. It?"

Sam just shook his head.

"How has this worked out for us in the past, huh Sam? You keeping secrets from me? Doing what you think is right? Where did that lead us?" Dean's gut clenches as his now stoic little brother flinches, knowing he hit home. He meant to, but it still hurts.

"No matter what. If I have any chance of being safe, I have to know what you know."

Sam's eyes flicked back and forth, his breathing speeding up a bit, almost imperceptibly. "Sam…"

"No one…not even- the angels don't know. Demons either."

Dean stared straight at Sam.

"Well I'm no demon and I ain't an angel." Sam was clenching his hands together tightly. "Sam-"

"I'm the Cage."

"…What do you mean?"

Sam turned his head, his expression betraying pure misery and self-loathing.

"To save…I had to-…Big brothers should protect little brothers, right?"

Dean flopped down in front of Sam, legs refusing to support him.

"Sam…what did you do?"

"I got Adam out and…I became Michael and Lucifer's cage."

Dean can't speak. His stomach's churning, his eyes stinging and no, no, no, not this…not to Sam.

"I had to…I had to…"

Sam's repeating it like a mantra. Dean thinks Sam should be crying, but he doesn't even know if Sam has the ability to look distressed anymore. He reaches out for Sam anyway, pulling him down with him. Just clinging onto what was left of his little brother.

Dean remembered that night at Cold Oak, holding Sammy in his arms, limp and cold. The desperation and the wrong and he understands, he really does. Big brothers and little brothers…

"I know, Sam. I know."

Because what else could he say?