Prosecutor Hwang Shi-mok underwent severe brain surgery as a child, after which he stopped experiencing emotions forever. He grew up calm, reasonable and lonely. In the prosecutorial profession, he is absolutely incorruptible. One day, Hwang goes to visit a former colleague and finds him in a pool of blood, who died an obviously violent death. One of the police officers who responded to the call turned out to be Lieutenant Han Ye-jin. From now on, the woman, along with the emotionless prosecutor Hwang, will have to fight corruption in the local prosecutor's office and the police.