While city dwellers Nora and Mimi have different experiences adjusting to their new surroundings, their first investigation is already underway: A fisherman has found a dead body in the harbor basin. It is apparently the rider of the stray, agitated gray horse that was captured near the harbor. It soon becomes clear that the man did not die of natural causes. Hinrichs wants the case solved as quickly as possible.

Real estate agent Jakob Niehues dies of anaphylactic shock during a skydive after being stung by a honeybee. His allergy medication is empty. Several people may have had a motive for his death: his neglected housekeeper Elly, the dancer Silke, or even amateur beekeeper Hannes. Nora and Jon investigate the case.