Marine biologist Heiner Lübbers is killed in an explosion. Since he actively opposed the deepening of the Elbe River, did he perhaps have a violent argument with Tanja Lorenz, who runs a terminal operating company? While diving in the Elbe, Heiner had taken samples to prove that deepening the river is destroying the Elbe’s ecosystem. And Ms. Lorenz had a heightened interest in seeing him and his analyses disappear. Suspicions against Tanja Lorenz continue to grow when she meets Robert Lohr of all people, who works for Elbe fisherman Erik Lübbers. Are the two of them working together?