Author's Notes: It's been forever since I updated, ah sorry about that. This is the shortest chapter, but it's also the second-to-last.
Sam sped on down the hallway, trying to figure out where the younger Dean had disappeared to. He stopped short when a plain brown door appeared at the end of the hallway. Taking a deep breath, he twisted the knob and let it swing open, unsure of what to expect.
It was the same scene he had seen before—Dean sitting on the motel bed, cleaning the rifles, lost in thought. He blinked, and the scene switched to the child's bedroom again: young Dean playing with his toy soldiers. Sam shivered.
"Hi, Sammy," came the innocent voice.
"Dean, what the hell is going on?" Young Dean looked up at him reproachfully.
"Daddy says you shouldn't say that word, Sam."
"Dean! We don't have time for this! If you spend any more time stuck in your own head, you're going to die."
The sound of the door opening came from downstairs, as John and Mary entered the house again.
"I have to go," said Dean quietly, pushing out his chair and standing up. "Mommy! Daddy!" he exclaimed, rushing down the stairs. However, this time when Sam attempted to follow him, he ended up in a completely different place: the motel room, again. Dean was still cleaning the rifles, and still lost in his own thoughts. Sam sat down on the opposite bed and watched him intently. Soon another figure entered the room, and Sam realized it was yet another Dean, a mirror image of the one cleaning the rifles.
"Have you figured anything out?" Dean asked. Sam turned around to face him. Dean had taken a comfortable, cross-legged position on the opposite bed.
"You have to stop this," Sam whispered. Dean shook his head.
"You have to! Dean, you're stuck on some sort of loop. Why do you keep bringing me back here? What happened here that's so significant?" Dean sighed.
"Do you really want to know?"
"Yes, I really want to know! What happened here, Dean?"
"This is where it hit me, Sam." Sam frowned.
"What hit you?"
"We can't save each other. The deal I made…you can't save me. And if I'm dead, I can't save you. It doesn't work." Sam was staring at Dean, a look of confusion etched on his face.
"So what, Dean? Then we find another way!" The young Dean shook his head again.
"This is where I gave up, Sammy. I finally—I just gave in. I decided that I didn't care anymore, and I didn't want to live, and I would die." He took a deep breath, staring down at the floor. When he finally mustered up enough courage to look up, his eyes showed no emotion. "And that is how I killed my brother."