I Saw the Devil

After the pregnant wife of secret agent Kim Soo-hyeon is brutally murdered, he begins a private hunt for Kyung-chul, a psychopath who kills for pleasure. Soo-hyeon tracks the serial killer down, but instead of handing him over or ending the pursuit with a single act of revenge, he sets out to make him suffer. As the chase continues, his determination to punish Kyung-chul pushes him toward the same mercilessness he is trying to destroy.