Åke is married and has a daughter of 11 years. He has a relationship with Ulla, who lives in the same house. Previously, Ulla had a love affair with Bertil, who lives and works on the same street. He spies jealously on Ulla and then discovers her relationship with Åke. One Saturday night Ulla is found dead by her landlady. Åke`s little daughter has witnessed who visited Ulla that evening.