A young Swedish secretary begins an affair with an older, married man whom she met at a scientific meeting in Stockholm. She is extremely tormented by their relationship, because the man refuses to divorce his wife. The young woman finally tells her boyfriend about her affair, then decides to leave both men. She accepts a job in Rome and is about to board her train when the older man stops her and tells her how much he needs her. They spend one last night together on the train, but in the morning she resolves to break off with him and begin a new life for herself.