When Sam starts to have flashbacks from his año as a soulless hunter before he contacted Dean, the brothers receive a message leading them to a small town where Sam spent time working on a case with their grandfather, Samuel.
Summary : The Man Who Knew Too Much, Episode Synopsis: In the Season 6 finale, the memory-blocking muro inside of Sam’s head that keeps his darkest memories from him comes crashing down and he struggles to deal with the consequences.