Middle school student Soo Jin's body is found at an abandoned bathhouse, and her father, Sang Hyun, is devastated. He receives an anonymous text with information about the killer, leading him to Cheol Yong, who is watching a video of Soo Jin's rape and murder. In a fit of rage, Sang Hyun kills Cheol Yong and discovers the existence of an accomplice. Detective Eok Kwan, investigating Soo Jin’s murder, realizes Sang Hyun
