Stranger (2017)

Hwang Shi Mok is an exemplary prosecutor who suffered from hypersensitivity to certain sounds. After undergoing a brain surgery in his youth he almost lost his sense of empathy. While investigating a strange murder case, he meets police lieutenant Han Yeo Jin, and she assists him in solving it. As they begin to unravel the mystery behind the murders, they also discover that someone guides and someone hinders their efforts to unfold the secrets about a larger scheme of corruption between the government's Public Prosecutor's Office and a private conglomerate.