The day before chemist Dr. Hans Wynhold leaves for a six months business trip to Africa, he meets chemistry student Christa Weiden. They spend the evening together in St. Pauli and fall in love. She doesn`t tell him that she`ll start the next day at the chemistry laboratory he works at too, because he says he doesn`t like women in "men`s jobs". Only after his departure the next day Christa learns about Hans` reputation as a Don Juan. In fear that she`ll lose him to another woman, she follows him... and starts a series of complications.