Leonard Shelby is tracking down the man who raped and murdered his wife. The difficulty of locating his wife's killer, however, is compounded by the fact that he suffers from a rare, untreatable form of short-term memory loss. Although he can recall details of life before his accident, Leonard cannot remember what happened fifteen minutes ago, where he's going, or why.

Headstrong yet aimless, Will Hunting has a genius-level IQ but chooses to work as a janitor at MIT. When he secretly solves highly difficult graduate-level math problems, his talents are discovered by Professor Gerald Lambeau, who decides to help the misguided youth reach his potential. When Will is arrested for attacking a police officer, Professor Lambeau makes a deal to get leniency for him if he gets court-ordered therapy. Eventually, therapist Dr. Sean Maguire helps Will confront the demons that are holding him back.

When timid bank clerk Stanley Ipkiss discovers a magical mask containing the spirit of the Norse god Loki, his entire life changes. While wearing the mask, Ipkiss becomes a supernatural playboy exuding charm and confidence which allows him to catch the eye of local nightclub singer Tina Carlyle. Unfortunately, under the mask's influence, Ipkiss also robs a bank, which angers junior crime lord Dorian Tyrell, whose goons get blamed for the heist.

A card shark and his unwillingly-enlisted friends need to make a lot of cash quick after losing a sketchy poker match. To do this they decide to pull a heist on a small-time gang who happen to be operating out of the flat next door.