In a remote inn in the Black Forest, police and Wehrmacht veterans celebrate a bloody slaughter fest. The self-righteous federal border guard officer Felix Krüger directs the event. Police officer Hans Cremer, who, like many "old comrades," continued to fight for the French flag in the Foreign Legion after the capitulation in 1945, transfers to the federal border guard and is appointed by Krüger, not entirely legally, as a special investigator. A trail of blood runs through the Black Forest and the adjacent Rhine Valley. An artist allegedly commits suicide. An employee of the Gehlen organization is executed. Girls disappear and reappear as corpses. Police officers are shot at, hunted, and murdered. Hans Cremer sees a connection between the attacks and murders in the tri-border area of Baden, Switzerland, and Alsace and crimes from World War II.