I suppose I should also point out that I Saw The Devil isn't nearly as good as I'd hoped. As South Korean revenge thrillers go, it's definitely South Korean and it's very revengey, but sadly it's not all that thrilling. In the admittedly lazy but inevitable comparison to Park Chan-wook's Vengeance trilogy, Kim Ji-woon's film comes off worst, substituting sympathetic characters and layered plotting with intense violence and wincingly visceral torture scenes.
The film is constructed around such a latticework of plot holes that it's a wonder it doesn't collapse in on itself. A rogue detective keeps track of a killer thanks to a combined homing device / microphone that the latter has swallowed, which inexplicably allows the detective to hear all the killer's conversations despite the microphone sitting somewhere in the depths of an intestinal tract; the police are staggeringly useless, preferring to stand around in turtle necks and puffa jackets rather than catch a dangerous madman who's astonishingly easy to catch for an off-duty detective; and the repetitive nature of the protagonist's plan soon becomes tiresome.
There's also a controversy-baiting rape scene that's led to I Saw The Devil remaining unrated by the BBFC for theatrical release and thereby receiving extremely limited distribution, meaning almost nobody will get to see the film at the cinema. Whether the film should be exhibited cut, uncut or at all will no doubt be a matter of some debate, but fans of controversy-baiting rape scenes can find out when the uncut, 18-rated DVD is released on May 9th. They should also probably seek some kind of help.
I Saw The Devil does boast some pitch-black LOLs, an impressively horrifying performance from Choi Min-sik and some bravura camerawork, but once you get past that all that's left is literally nerve-shredding body horror, arguable misogyny and graphic beatings, and frankly I'd rather watch a man eating a live octopus.