Baek Hee-sung (Lee Joon-gi) is a man who hides his identity and past from his wife Cha Ji-won (Moon Chae-won), a detective. On the surface, they appear to be the perfect family: a loving couple with a beautiful daughter who adores her parents. Cha Ji-won and her colleagues begin investigating a series of unexplained murders and is confronted with the reality that her seemingly perfect husband may be hiding something from her.
