Like every summer, Helge Stuhr relaxes in St. Peter-Ording. There, he meets people in a cheerful setting who work in the energy trade and aren't too strict about the truth. Unexpectedly, he is summoned to Rendsburg by his friend Commissioner Hansen. A department head of the municipal utilities has been decapitated by a wind turbine. It quickly becomes clear that the crime followed the same pattern as two other murders. However, it remains unclear where the trail leads...