An idea I couldn't resist after watching that awesome premier :)
Sam stared at the window of Dean eating dinner with Lisa and Ben. It warmed his heart to see that Dean was actually doing what he had promised to do. He could barely feel the rain. He felt almost completly numb. Every fiber in his body wanted to go to the door and ring the doorbell but something kept him away.
After everything that happened Dean deserved this. He had earned a normal life. He had gotten out. He didn't die in his 30's like most hunters did. He survived and got a happy ending, almost a happy ending. If Sam called him he would be dragging Dean back into his mess, into that life.
No, Dean deserved better. He'll get over it. He'll move on. He'll live that normal apple pie life that Sam so desperatly wanted, but could never have. He saw that now. He also knew that Dean,deep down, had always wanted that life too despite how often he had denied it.
It caused Sam to ache as he thought about being by himself, but this was his punishment. This was what he deserved. He had to stay away, for Dean's own good.
His mind flashed to hell as he walked away.
Lucifer taunting him in his mind.
"I'll make you pay for this Sam Winchester!" And forcing his body to go after Adam/Micheal. Adam had already siezed control of his body as well and screamed in pain as Lucifer forced Sam to claw at his own brother, to attack him...to tear him limb from limb so he could be put back together again.
Sam pushed those thoughts out of his mind. He walked out into the night, determined to keep a safe and far off distance from Dean.
Each day started out the same. Sam gambled a bit, and played games of pool for money in order to save up to get a car. Each motel room got worse and worse.
He felt a distant ache in him when he said "Room with one bed." He swallowed as he looked around the small room. Memories of him and Dean swiping stories and muling over what new monster they were dealing with.
Now it was just him, flying solo.
Suddenly there was a knock on his door. He froze. Why would ANYONE be wanting to talk to him? Suspicion surrounded him as he got up slowly and grabbed his gun. Aiming it at the door he opened it. An older man was there and rose his hands when he saw Sam.
"Don't shoot!" He said quickly. "This...this is going to be hard to explain, Sam."
"Who are you?" Sam shouted, his voice dark and angry.
The man sighed.
"I'm Samuel Campbell." He stared into Sam's Winchester's eyes. "I'm your Grandfather."