Ki Hoon gets arrested for murdering his girlfriend, and the Daebong-dong case is finally closed. However, Ha Young cannot let go of this case, as he believes that the real culprit is still out there, committing another crime. Therefore, he visits an inmate he met at his station and interviews him to study the minds of criminals. Meanwhile, Captain Park is not happy with him since he is going after the case he has already finished.
