One night, Dae-su (Choi) is locked up in a mysterious prison - with no idea why. After 15 torturous years, he's suddenly released and given a mobile phone, a designer suit and a wallet full of cash
No doubt about it, OldBoy is all about extremity. You want torture? Try getting your head around the idea of being in solitary for 15 years. Violence? Check out the one-take corridor brawl in which psychologically ravaged Dae-su takes on a score of goons... with a claw-hammer.
You want to know how far someone could go to wreak revenge? Well, we advise you to brave South Korean writer-director Park Chan-wook's helter-skelter descent into the dingiest pit of human behaviour, even if at times it is tough going and ludicriously unfeasible.
As Empire viewed a pre-BBFC-scrutinised cut of the movie, the infamous live-octopus-eating scene remained intact; it's doubtful this truly stomach-churning moment will make it into UK cinemas. But there's plenty else to shock even without it - and all done with such unabashed verve that you'll be as compelled as you are repulsed.
OldBoy recalls Fincher in its CG-assisted flourishes and doomy themes, and Tarantino with its sharp-suited, stylised bloodletting. But it's unlikely either of those guys would ever be allowed to push it as far as Park has with this. Like we said, the word is extreme...
Not to everyone's tastes, but if you have a strong stomach, OldBoy is sure to impress.