A serial killer whose mother was a prostitute starts killing streetwalkers as a way of paying back his mother for her abuse.

Oscar Bänz is a solid, middle-class taxi driver and widower. He loves his daughter Irma with all his heart. In order to provide for her, he has not remarried. Irma, a quiet, intelligent young woman, is studying medicine. To finance her education, Bänz rents a room to Toni Schellenberg, a young man from the countryside with a promising future as a soccer player. But the big city, easy money, and superficial friends cause Toni to neglect his training and evening classes, and eventually his employer fires him. Irma, who has fallen in love with the handsome athlete, asks her father for help. He is finally able to find Toni a job as a taxi driver. But when Irma attends a student party and also agrees to a date with the senior physician Dr. Zbinden, Toni feels neglected.

Willy Guggenbrühl is a meticulous bank clerk and an extremely shy person. Over time, this leads to his wife Margit becoming bored with him and eventually filing for divorce. Now the otherwise reserved Willy finally awakens from his lethargy and decides to win Margit back. On the advice of his old childhood friend Roger, he decides to make his wife jealous, which sets off a whole series of turbulent developments...