In 1986, in the provincial town of Hwaseong, two local women were killed in the same perverted way. Detective Park Tu-man and his assistant Cho Yong-gu are trying with all possible zeal to find the killer. More precisely, they force any suspect to confess to what he has done, and they do it using the most brutal methods. Detective Seo Tae-yoon from the Seoul, to conduct an investigation and identify the maniac based on evidence and evidence. Meanwhile, the killings continue.