Through the Darkness

Song Ha-yeong pursues a criminal known for targeting young women. Kook Yeong-su looks to form a team of criminal behavioral analysts.

Ha-yeong consults a criminal to understand a killer's motives. An arrest leads to a startling interrogation session and a break in the case.

Another murder occurs in Changeui-dong; Ha Young wants to join Tae Gu from the Special Crime Squad.

When a suspect's home is searched, the police make a gruesome discovery. Ha-yeong and Yeong-su grow frustrated as the investigation continues.

A crooked new police chief causes trouble for the team. The deaths of a professor and his wife touch off a series of brutal murders.

Yoon Tae-gu and Kim Bong-sik seek to set boundaries on the behavioral analysis team. A complex investigation sends the police down a twisted path.