How do you face life when your memory is shattered? This is what happened to the protagonist of this film. Leonard Shelby (Guy Pierce) was attacked by gangsters at home, his wife was brutally raped and killed, and he also suffered serious brain damage. After waking up, he found that he had a rare "short-term memory loss disorder". He could only remember what happened more than ten minutes ago. In order to keep his life going and to avenge his wife's tragic death, he used tattoos, notes, Polaroid snapshots and other small things to preserve his memory, collect clues, and launch a difficult investigation. During the investigation, Leonard met Natalia (Carrie-Anne Moss), a vulgar barmaid who seemed to know something that Leonardo was interested in; and Teddy (Joe Pantoliano), who claimed to be his former good friend, but looked sneaky and had bad intentions. Who can he believe? Natalia? Teddy? Or himself? After unraveling the mystery, the truth is revealed, simple yet cruel. Does Reiner have the courage to face it all?