In 1988, a businessman named Oh Dae-su is arrested for drunkenness, missing his daughter's fourth birthday. After his friend Joo-hwan picks him up from the police station, Dae-su is kidnapped and wakes up in a sealed hotel room, where food is delivered through a trap-door. Watching TV, Dae-su learns that his wife has been murdered and he is the prime suspect. He passes the time shadowboxing, planning revenge and attempting to dig a tunnel to escape. Fifteen years pass since he was imprisoned. It is now 2003, a new millennium. Just before digging himself to freedom, Dae-su is sedated and hypnotized. He wakes up on a rooftop and sees a man on the ledge ready to jump to his death. The man asks him, "Even though I am no better than a beast, don't I have the right to live?" Dae-su leaves the man and tests his fighting skills on a group of thugs. Afterward, a mysterious beggar gives him money and a cell phone. Dae-su enters a sushi restaurant where he meets Mi-do, a young chef. He receives a taunting phone call from his captor, collapses, and is taken in by Mi-do. In a frenzy, Dae-su tries to force himself on Mi-Do in the bathroom of her apartment; however, she is armed with a knife and successfully fends him off. Dae-su attempts to flee the apartment, but a sympathetic and intrigued Mi-do confronts him. Mi-do explains to Dae-su that she is romantically interested in him, but that they hardly know each other and she is not ready to be intimate. They reconcile and begin to form a bond. After he recovers, Dae-su makes an attempt to find his daughter. Discovering that she was adopted, he gives up trying to contact her. Now focused on identifying his offenders, he locates the Chinese restaurant that made his prison food and finds the prison by following a deliveryman. It is a private prison, where people can pay to have others incarcerated. Dae-su tortures the warden, Mr. Park, who reveals that Dae-su was imprisoned for "talking too much". He is then attacked by guards and is stabbed but manages to defeat them.