To combat rising violent crimes, the Police Chief asks Detective Oh Goo Tak (Kim Sang Joong) to form a team consisting of criminals. He is currently suspended from the police force for using excessive force. He then gathers team members: Park Woong Chul (Ma Dong Suk) who is a gangster, Lee Jung Moon (Park Hae Jin) who is the youngest serial killer with extraordinary intelligence, and Jung Tae Soo (Jo Dong Hyuk) who is a contract killer. Police Inspector Yoo Mi Young (Kang Ye Won) also joins the team and she tries to have these guys work as a team by dealing with them rationally and sometimes emotionally.
