David Aames (TOM CRUISE) is a successful, thirty-something playboy who inherited his father's publishing business but would rather spend his time snowboarding or bedding attractive young women like Julie Gianni (CAMERON DIAZ). That, of course, doesn't sit well with his board of directors despite the loyalty of his father's confidant, Thomas Tipp (TIMOTHY SPALL), and makes his friend, Brian Shelby (JASON LEE), somewhat jealous of his cavalier lifestyle.
The latter only gets worse when Brian brings the ravishing Sofia Serrano (PENELOPE CRUZ) to David's birthday party and the two immediately hit it off. After spending the night together, the two seem to be walking on clouds, but David then runs into Julie who seems to be stalking him as she's upset about not being invited to the party and his lack of love for her.
Accordingly, she drives both of them off a bridge, killing herself and injuring David, leaving him with a disfigured face. David then finds himself in a world where reality isn't what it always seems. Hidden behind an expressionless latex mask and incarcerated in prison for a murder he doesn't remember, David thinks his board set him up, a point that McCabe (KURT RUSSELL), a sympathetic psychiatrist assigned to his case, doesn't believe.
From that point on, and as the story jumps back and forth through time, David tries to get his life back in order, all while repeatedly seeing programming about cryogenics, having repeated run-ins with Edmund Ventura (NOAH TAYLOR), a mysterious man who claims to know him, and seeing people and experiencing events that may or may not be real.