Hiding a twisted past, a man maintains his facade as the perfect husband to his detective wife — until she begins investigating a series of murders.

A young girl named Hye-Na is abused by her mother, Ja-Young. Although she is not okay, she tells other people she is alright. Soo-Jin is a temporary teacher at the elementary school where Hye-Na attends. Soo-Jin is aware of her situation and decides to become her mother.