Dr. Peter Hauser is very pleased with his life: he has not only taken over his father’s medical practice in the town where he was born but also found true love in the form of Italian beauty Stella Calvani. Stella soon moves into the doctor's house with her two lively sons, and before long Peter is determined to secure his happiness for ever: he proposes to her, and she accepts in delight. When Peter’s father Dr. Heinrich Hauser returns from a cruise, Peter and Stella intend to surprise him with their news - but things don't quite work out that way. Because Heinrich himself has a big surprise for them, which he proudly presents the moment he arrives: Johanna, a vivacious three-times widow he met on the cruise and married on the spur of the moment. The family are staggered - and Peter is particularly suspicious. It's not only that his father has upstaged his own approaching wedding to Stella by getting in first (yet again); Peter also suspects that Johanna is a murderous gold-digger who already has three husbands on her conscience. Peter’s sometimes clumsy attempts to expose Johanna bring him to the point where he is risking a great deal: the family is in danger of splitting up... until he also recognizes that love is the greatest gift.