Kang Woo Hyun is brought into the emergency room due to numerous injuries. There, he claims that he has been hunted by people, and his family is missing. Ko Dong Guk, a detective nearing retirement, is dispatched to take care of it.

A detective falls of a roof and dies, but Dong Guk believes the detective was murdered. A criminal profiler, Yoon Seo Young, joins the investigation, but Dong Guk refuses her help.

The search team find Woo Hyun's son's body. As someone with experience in losing a child, Dong Guk gives Woo Hyun a piece of advice. Soon, they find out that CEO Hong may be involved in Woo Hyun's case.

Strings are pulled to cover up CEO Hong's mistake, and the team in charge of Woo Hyun's case are reassigned. Dong Guk and Seo Young head over to Woo Hyun's house to gather evidence that can reveal the truth.

To provoke CEO Hong, Seo Young decides to go on the news and claim that they are close to catching the perpetrator. Naturally, being an ostentatious psychopath, CEO Hong decides to kill them before they get any more evidence.

Dong Guk is trying to lay low and forget about the case after what happened to Seo Young. Meanwhile, Woo Hyun is trying to prove himself to the same group that were hunting him down, in order to join them.