Professor Gotthold Kittguß leads a secluded life, which is primarily determined by his books. His housekeeper, the widow Müller, takes care of all the practicalities of life. One day, a strange boy appears at his house to deliver a call for help from his 17-year-old godchild Rosemarie, who is the daughter of a deceased pastor friend and lives with the Schliekers, her so-called foster parents, in the small village of Usadel. The Schliekers manage Rosemarie's inheritance, but are anxious to take possession of the farm. They treat Rosemarie like their maid and allow her to live in undignified conditions. After a moment's hesitation, Professor Kittguß sets off for Usadel to help his godchild. But he doesn't receive a warm welcome there and is even locked up in a cellar. Rosemarie frees him and takes him to a secret hiding place in a nearby fisherman's hut.
