How long can you hold your breath? One minute, maybe two? That won't be enough... Air! Desperately, he pounded his fists against the glass. His eyes were wide open and painful. He felt the pressure threatening to burst them from their sockets. But even more, his lungs were burning. He needed air! A dead man is floating on the Weser at the ship mill in Minden. But it quickly becomes clear that he did not drown in the river. For the Minden commissioner Marlene Borchert and her colleague Benno Erdmann from Bielefeld, a race against time begins across OWL, ultimately leading them to the depths of the human soul.