Starring Min-sik Choi and Ji-tae Yu. In Korean with English subtitles. Rated 18A. Opens Friday, April 15, at the Granville 7

One of the reasons for the stratospheric rise of South Korean cinema in international critical esteem stems from the way this imaginative film industry plays fast and loose with generic conventions. Memories of Murder, for instance, a film inspired by the emergence of that country's first indigenous serial killer in the 1980s, managed to cross the codes of the slasher film and the policier in a way that made a brilliantly heterodox political point. Its director, Joon-ho Bong-who was highly critical of his homeland's recent dictatorial past-suggested that torture is not only wrong but is also ineffective because if all suspects are brutalized in exactly the same way, all will eventually confess to exactly the same crime.

If anything, Oldboy is even more disrespectful of established conventions. It's the story of Dae-su Oh (played by Min-sik Choi), who is imprisoned for 15 years without a word of explanation, only to be suddenly released and actively encouraged to punish the people who have imposed this inscrutable punishment upon him. The film invites obvious comparisons to The Prisoner, The Count of Monte Cristo, and The Trial, but-here comes the unorthodox part-there are also more subtle references to Oedipus Rex.

Routinely described as a revenge drama, and sold with a trailer that makes it look like a vintage John Woo bloodbath, Oldboy is actually anything but a straightforward action flick. Dae-su Oh, for instance, the film's black-clad hero, was not a particularly nice guy even before his abduction, and his mental list of people who had scores to settle with his sorry ass tops 200. Oh is also prone to eating live octopi and questioning suspects with the claw end of hammers. (Whatever you do, don't see this film if you're planning to visit the dentist or eat sushi!)

Who is doing what to whom, and why, is a mystery that won't be fully resolved until the final frames, with an ending to intentionally dissatisfy everyone.

Ironically, this cathartic implosion is probably the best thing about a film that is otherwise chock-full of brilliant narrative leaps and technical savoir-faire. Despite his potentially exploitive subject matter, director-cowriter Chan-wook Park is an artist to the tip of his camera boom, and he delights in manipulating us the way that Dae-su Oh's antagonist manipulates him. Oldboy's hero might settle scores with a hammer, but his creator prefers the more insidious penetration of the stiletto.