Restless activity at the tiger enclosure. When the predator emerges from the water, the idyll at the Cottbus Zoo comes to an abrupt end: a human arm protrudes from the animal's mouth. Commissioner Peter Nachtigall and his team begin their investigation. Does the arm match the current missing person's report? And where are the other body parts? Nachtigall becomes entangled in a web of dangerous secrets and mysterious family ties.