Decalcomanie

Hyun-jae finds a clue from Ha Tae-sik that leads him closer to "The Guy". While chasing the lead, Hyun-jae learns of the existence of a psychiatric ward, and Soo-young discovers an unexpected commonality among the serial murder cases. Meanwhile, a hanged body is found in a mountainous area of ​​Soo-young's hometown, Hwayoung-gun, and Team Leader Hwang Ha-young proposes sharing information with an unexpected individual...