After the death of Min Ji, who showed trust in Tae Joo, Tae Joo meets Si Yeong and suggests catching the serial killer together. Tae Joo’s comeback arouses controversy among his colleagues, but he just focuses on tracking the killer. He discovers a connection between Min Ji and Gi Beom. To make things worse, Gi Beom becomes the suspect because of the assault on Jeon Kyung Ho, and the doubt toward him becomes stronger.