Dan Hyeon, a city shrouded in corruption and unsolved mysteries. Cold-hearted prosecutor Ju Tae-seon despises murderers to the core, while investigator Lee Chae-ha has spent his entire life barely surviving under the stigma of being the “son of a killer.”

On his first day after being transferred to prosecutor Tae-seon’s office, Chae-ha realizes that the case Tae-seon is pursuing is far more than an ordinary drug case.

The casino mogul murder case from years ago left deep wounds in both men’s lives. Yet Ju Taeseon unexpectedly proposes to Lee Chaeha that they reopen the investigation.

While investigating a murder case disguised as an accidental fire, Ju Taeseon and Lee Chaeha show flawless chemistry. Are their feelings about to cross the line?

As the investigation takes a dangerous turn, Lee Chae Ha uncovers new clues that challenge everything he believed about the long-unsolved murder case.

After a shocking attack leaves Chae Ha in danger, Tae Sun can no longer hide how deeply he cares for him.