Middle-class housewife Ae-soon (Moon Yae-bong) is excessively vain and neglectful of her duties as a homemaker. Unable to tolerate her any longer, Ae-soon's husband (Lee Keum-ryong) kicks her out, and she leaves him and their daughter Jeong-hee (Yoo Sun-ok) to take up with her lover in a hotel. One day, she finds out that her lover is not a wealthy bigshot after all, but a poor lodger and a criminal to boot. She reports him to the police for a robbery he has committed, and decides to go to Busan after handing him over to the authorities. Speeding in order to catch her train, she accidentally runs over her own daughter. Jeong-hee is rushed to the hospital, where she safely regains consciousness, but Ae-soon is wracked with guilt and resorts to suicide.