Dae-hoon is a special agent whose pregnant wife becomes the latest victim of a disturbed and brutal serial killer. Vowing revenge, Dae-hoon blurs the lines between hunter and hunted and good and evil, eventually becoming a monster himself in his twisted pursuit of revenge. "I Saw the Devil" is shockingly violent and stunningly accomplished, transcending the police procedural and pushing the boundaries of extreme Asian cinema in surprising and thrilling new ways.