Taken without reason; imprisoned for 15 years; released without reason. 5 days to seek the truth...

One day in 1988, ordinary white collar worker Oh Dae-soo is kidnapped and incarcerated in a private makeshift prison cell, dressed up like a cheap hotel room. With only a TV for company, Dae-soo makes numerous attempts to escape and to commit suicide but they all end up in failure. All the while Dae-soo asks himself what made a man hate him so much enough to imprison him in solitary confinement with no explanation. While suffering from his near-madness, Dae-soo becomes shocked when he watches the news and hears that his beloved wife was brutally murdered. At this very moment, Dae-soo swears to take revenge on the man who destroyed his happy life.

15 years on and without a word of warning Dae-soo is released. Given a new set of clothes, a mobile phone and the attentions of curious sushi waitress Mido, Dae-soo begins to track down his enemy, only to find he may be the pawn in a much bigger game which is only just beginning. Taunting Dae-soo, the culprit gives him just 5 days to catch and kill his captor or Mido will die...

Based on Japanese manga of the same name by Minegishi Nobuaki and Tsuchiya Garon, 'Old Boy' is a masterfully inventive revenge thriller complete with blackly comedic moments.