In a lake on the edge of the Swabian Alb, an employee of the small local energy supplier is found dead - sunk in the water with a stone around his neck. He had the task of following the developments on the Leipzig electricity exchange on a daily basis in order to order the demand for the next few years when the quotations were favorable. In the apartment of the murdered man, Inspector August Häberle finds several video films. The dead man had apparently produced documentaries about the energy industry and only a few days ago had conducted a critical interview with a high-ranking manager of an energy giant. When Häberle learns a short time later of another body discovery in faraway Mecklenburg-Western Pomerania, he pricks up his ears: just like in his case, the man had been "sent" to the bottom of the lake with a stone around his neck ...