Detective Oh Byeong-ho (Hah Myung-joong) of the Munchang PD gets assigned to the murder of Yang Dal-su. As he follows the trail of clues, Oh begins to seek out the people linked to Yang Dal-su's past. He learns that a man named Hwang Ba-wu had harbored a grudge against Dal-su. He also meets Kang Man-ho, who is somehow connected to Ba-wu, and Sohn Ji-hye, a former mistress of Dal-su's who now works in a bar. During the course of his investigation, Oh discovers a shocking secret: Han Dong-ju, the murder victim in the case that put Ba-wu behind bars, is still alive…