After much hesitation, the doctor, who fell in love, Peter Hauser finally managed to make his girlfriend Stella a marriage proposal. But when the two want to surprise his father Heinrich with the good news, the one holds much greater surprise ready: On holiday, he has fallen in love with the attractive widow Johanna and married her right away. Peter is anything but excited. He believes that Johanna is a notorious husband murderer. However, in trying to gather evidence of his suspicion, the awkward amateur detective moves from one fool to the next.