Prosecutor Hwan Shchi-mok underwent a major brain surgery in his childhood, after which he permanently ceased to experience emotions. He grew up stoic, rational, and solitary. In the prosecutorial profession he was utterly incorruptible. One day Hwan went to visit a former colleague and found him lying in a pool of blood, apparently the victim of a violent death. One of the police officers who arrived in response to the call was Lieutenant Han Ye-jin. From that moment, the woman, together with the emotionless prosecutor Hwan, will have to fight corruption within the local prosecutor's office and the police.