Frido Schulz and Rosa Schätzlein have known each other since their student days. But while Rosa made a career as a lawyer, Frido had to take over his father's electrical store. Since then, he and Rosa have been like cats and dogs, even though they are neighbors and Frido's wife Hanne is Rosa's best friend. But then Hanne dies. Her sudden death only exacerbates their relationship as neighbors. Frido's accusations against Rosa reach their climax when he drags her to court for theft: She is accused of stealing his little black cat, which had run into him one evening.