Ko Sun-young is a popular television announcer and midnight DJ on a show that mixes film analysis with selected songs from the associated soundtracks. Sun-young decides to quit her job after her daughter, Eun-soo, requires heart surgery that is only available in the United States. On her last day of work, Sun-young's sister Ah-young babysits Eun-soo at Sun-young's apartment. While she is on the air, Sun-young receives a call from a man named Han Dong-soo, who claims to be her fan. Inspired by Travis Bickle, the unstable vigilante from ''Taxi Driver'', Dong-soo has begun to murder pimps and drug dealers throughout the city. When he hears about Sun-young's imminent retirement, he takes her family hostage and demands that she retool her final broadcast to his specifications. However, Sun-young's boss discards the new playlist on the assumption that Sun-young herself submitted it.