I SAW THE DEVIL is a shockingly violent and stunningly accomplished tale of murder and revenge. The embodiment of pure evil, Kyung-chul is a dangerous psychopath who kills for pleasure. On a freezing, snowy night, his latest victim is the beautiful Juyeon, daughter of a retired police chief and pregnant fiancée of elite special agent Soo-hyun. Obsessed with revenge, Soo-hyun is determined to track down the murderer, even if doing so means becoming a monster himself. And when he finds Kyung-chul, turning him in to the authorities is the last thing on his mind, as the lines between good and evil fall away in this diabolically twisted game of cat and mouse.