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...