If it was in your power to pursue the serial killer who murdered a loved one, would you take the opportunity to seek revenge? That's the question that this violent and compulsive action/horror/thriller movie asks, as Kim Soo-hyun, a badass secret service agent in South Korea, sets out to find the man who brutally raped and murdered his fiance. The serial killer in question is Jang Kyung-chul, who is played in a typically disturbing fashion by Oldboy's acclaimed actor Choi Min-sik. Much of I Saw the Devil sees Kim Soo-hyun and his target beating the living hell out of each other across a number of beautifully shot and wonderfully choreographed - not to mention dizzyingly violent - action set pieces. Interestingly, the film leaves you wondering whether the "hero" of the picture is really a hero at all, as Kim Soo-hyun's morals are compromised and destroyed across the span of his obsessive quest for vengeance. This is a serial killer flick that kicks you square in the teeth and leaves you to bleed.