In front of the church in Niederbroich, Kati Küppers encounters the Jack Russell Filou. During a walk in the woods, he discovers a corpse infested with maggots, which the police cannot identify. Forensic expert Natalie also reaches her limits. Only an expert can help here: godmother Biggi, a professor of entomology and Kati's best friend. To the annoyance of Commissioner Rommerskirchen, Kati soon becomes deeply involved in the investigation. Not only does she ask the right questions, but she is also constantly in the right place, such as at the Bongarz bakery, where the latest rumors are whispered.