Sam has a twin brother, William. On the night of his 11th birthday, William disappeared into the motel just after blowing out his birthday candles.
Until he was seventeen years old, the second son of the Winchester family knocked on the door home.
William looked at Dean with an apologetic look, then turned around and disappeared into the air without mercy. Dean looked at his disappearing back with a pale face and despair, he had lost his brother again.
He vowed that no matter heaven or hell he would get his Willy back.
William, who returned for the second time, found himself locked in the room by his elder brother and younger brother, and he accepted it calmly with a look of helplessness.
Sam shrank into William's arms as he was used to, and said gloomily: "Don't even think about leaving, Willy, I will catch you.
William looked down at his younger brother who looked aggrieved and his angry brother standing at the door, neither agreeing nor rejecting.
This time the Winchester family can fight ghosts together again.
The idea: to fight ghosts as a family.