I Saw the Devil (Korean: 악마를 보았다; Hanja: 惡魔를 보았다; RR: Akmareul boatda) is a 2010 South Korean action thriller film[3] directed by Kim Jee-woon and written by Park Hoon-jung. Starring Lee Byung-hun and Choi Min-sik, the film follows NIS agent Kim Soo-hyun (Lee), who embarks on a quest of revenge when his fiancée is brutally murdered by the psychopathic serial killer Jang Kyung-chul (Choi). I Saw the Devil made its premiere in the United States at the 2011 Sundance Film Festival and had a limited U.S theatrical release.[4]