Alone in the void, inside his own head, Sam has plenty of time to think. What's so special about a soul anyway? Sam wonders again. Why was everyone so sure I didn't have one ?
Sam had been too busy trying to reason with Dean - to stop Death from shoving the soul back in to really think about it at the time. The soul had been bright - blindingly bright. Yet he knew human souls became demonic in Hell. So then why hadn't the soul shown any darkness? That soul had spent nearly two centuries as the Devil's punching bag and came out untouched. What had Death done?
Sam knew, logically, that he had been lacking something. Whatever it was that made him Dean's brother, Sam. What was a soul anyway? Whatever it was - a collection of emotional responses, a moral code, a lifetime of acquired guilt - he still couldn't understand why it mattered.
Sam had lived. He had spent a year and a half living - breathing, hunting, fucking. He still remembers all of it, and he remembers his past too. He remembers the Cage, and he remembers Lucifer's rage when his vessel had simply fallen through the bars and back up to Earth.
Sam leans back against the Wall, and looks into the void. He is alone here. Forever. It isn't fair. There must be more to a soul than feeling, because right now he feels angry.
He turns and faces the Wall, fingers idly running over its smooth, cold surface - and pushes. For the first time since he got here, he can feel the Wall start to give, ever so slightly.
"I'm just trying to make you feel better. Don't be a bitch." Dean snaps.
"Yeah, I'm fine." Sam says, moving away from his bed.
"Yeah, you look fine. All I'm saying is everything's gonna be okay." Dean says.
"I don't know, Dean. If I did this here, then who knows how many oth-"
Sam collapses to the floor and remembers
There is a piercing, pained scream from somewhere in the dark, and suddenly Sam knows he isn't alone anymore. He sees himself his other self suspended in midair and he's burning, and he's screaming. Sam moves forward, curious.
"Sammy? Sammy?" Dean runs over and kneels next to Sam's spasming body. Sam's eyes are open, but their focus is elsewhere
"Sammy, talk to me! Sam? Sam. S-sam? Oh, come on." Dean shakes Sam forcefully. "Sammy! Come on, come on. Come on, damn it."
Sam lets out a surprised gasp as the mirage/vision/memory of himself burning jerks forward suddenly and crashes through him and into the Wall.
The Wall looks solid, but Sam knows something has changed. He's shaky, and he doesn't know why. He's in pain and he doesn't know why. He feels like he's filled head to toe with burning embers and suddenly he understands.
In here, time means nothing. Sam doesn't know how long he waits until the next memory comes hurtling out of the emptiness. He knows that the intervals have been getting shorter and shorter, and he knows exactly what to do. He runs and intercepts it, feels it slam into him, change him, and he feels the expected pain, anger, and self-loathing. This time is different though. This time he feels pleasure.
Lucifer hadn't been lying when he told Sam that he knew him better than he knew himself. Lucifer understood Sam on every level. Lucifer knew exactly what would break Sam, and break him he did. Not with pain, but with everything Sam had always denied himself. Sam's body had been made for Lucifer. It was capable of holding more power than any human had any right to wield.
Sam knows that he'd had power once. In his year and a half he had on several occasions attempted to use his power. Why not? There was no reason not to use every weapon at his disposal. Of course, he had no intention of drinking demon blood. He remembered that too. The blood made him weak. He didn't want to be weak. He had tried to use his power, to draw it up from within, like he remembered, but he'd felt nothing.
As this memory of the Cage floods his thoughts, Sam remembers Lucifer's grace and his own power flowing into and through each other. He had never felt so strong and he had never felt so whole.
Now he understands. The power wasn't just tied to his body, it was tied to his soul, but his soul had rejected it over and over and over. His power was buried in here, and under Lucifer's care it had grown.
Sam falls back against the Wall - dazed, and happy. He puts his right hand against the warped, uneven surface, pushes, and feels it crack.
Despite everything, despite all the evidence to the contrary, Dean desperately wants to believe that Death's wall will last. So when Sam collapses again in the middle of a hunt (for the second time this week), Dean remains impressively calm.
Sam has gone completely still this time. His eyes are closed, and he looks almost like he's sleeping.
Dean shakes Sam's shoulder gently , "Come on kiddo. Time to wake up. "
Sam doesn't react.
Dean shakes Sam a bit harder, "Sam. Sam! Come on, come on. Snap out of it!" Dean sits back on his heels and tries to breathe, to slow his heart down a little. He leans forward again and slaps Sam's cheek hard.
Sam breathes in sharply and his eyes fly open.
Dean jerks back because he knows those eyes, and they aren't his brother's.