A case, two stories. Before the opening of a unique prehistoric exhibition at the Osterei Museum in Sonnenbühl-Erpfingen, a human bone is discovered among the exhibits from the Bear Cave. Commissioner Andreas Clemenz is on vacation. Since he has chosen to stay at his relatives' farm, he finds himself unintentionally in the midst of the events. Chief Commissioner Magdalena Mertens relies on unconventional investigative methods when it becomes clear that it is a murder case.