Stranger

The prosecutor's office and the police find themselves on opposing sides. The prosecutors, including elite prosecutor Woo Tae-Ha, want discretionary power over investigations. Meanwhile, the police, including Choi Bit, tries to get complete investigative authority that is independent of the prosecutor's office. Under this tense situation, Prosecutor Hwang Shi-Mok and Detective Han Yeo-Jin chase after the truth in a hidden case.

Hwang Shi-Mok had brain surgery when he was a child, which caused him to lack emotion. Now, Hwang Shi-Mok works as a prosecutor. He is rational, but cold and lonely. He is also one of the only prosecutors not involved in corruption. One day, a dead body is thrown in front of him. He meets Police Lieutenant Han Yeo-Jin at a murder crime scene. They work together to eradicate corruption at the prosecutor's office and solve a serial murder case.