Sun-young is a popular radio DJ with for a cinema music program that is aired live at midnight. She is a perfectionist who has built a successful career for the past 5 years, but when her young daughter needs a surgical operation overseas, the single-mom decides to quit. She prepares for her final show from song selections down to the smallest details. During the show, she receives a call from a listener named Dong-soo. He tells her that she must follow his orders while she hosts her live radio show, or her family's lives will be at stake, and threatens that she can't tell anyone.