Sam heard his brother talking to Bobby just as he was about to enter the motel room. He wanted to confront his brother, God knew he wanted to but he knew that this was his destiny. That he was gonna become something his family hunted. He didn't go inside and instead went in the car and cried his eyes out. He wanted the pain to end. It was just too much. He cried until the tears dried out and Dean came out of the room and sat in the driver's seat. The ride was silent until they almost reached the destination to kill leshi. Dean knew something was wrong. He turned to look at his brother who was looking out of the window, as he was like avoiding Dean's eyes. Then dean saw the tears and he frowned. "Sammy? You crying?" he asked. "No" Sam replied and still continued to look outside the window. Dean sighed and carried on with the ride.
They had killed leshi. It was a win. Sam was sitting inside his motel room bed while Dean was taking care of the body. Sam took out the demon killing knife. He thought this was the most fitting way to die. He brought the knife to his arm and cut two deep slashes on his arm and then two more long slashes across the other arm. Blood started to come out of the slashes and his vision started to fade out and he falled on the floor, his last thought being I'm sorry, Dean as his vision faded to black.
"C'mon Sam, let's hit the ro..." Dean came in announcing and froze at the scene. His brother was lying out cold on the floor with his blood surrounding him. "Saammm!!!!" he screamed and slid beside his brother. He checked his brother's pulse, exhaling that it was still there. "Hey, Sammy, wake up, come on" he tapped his cheeks but Sam wouldn't budge.
"Cassss!!!!!!!" Dean screamed and Castiel was there in an instant. He saw the scene and Dean crying and pleading with his eyes. "Step aside, Dean" Cas said and started to heal Sam. Slowly the cuts healed and Sam relaxed. "I have healed his cuts but his blood loss, I couldn't heal that" he said and Dean nodded. "Why would he do this?" Dean asked, whispering. "Maybe he thought he was alone, that he had broken the world, that it was better to stop Lucifer from getting his vessel, maybe that pushed him to the edge" Cas said.