watch I Saw the Devil full movie online HD 123movies, $title full movie online Gostream plot:Kyung-chul, a dangerous psychopath who kills for pleasure, has committed horrifying and senselessly cruel serial murders on defenseless victims. One day, Joo-yeon, daughter of a retired police chief becomes his prey and is found dead in a horrific state. Her fiancé Soo-hyun, a top secret agent, decides to track down the murderer himself..