The body of a young woman is found on the shores of Lake Constance. The next day, her superior, the biotech luminary and Nobel Prize winner Bernd Eschenbach (Peter Benedict), is discovered dead in the lake - bound hand and foot. The old legend, according to which delinquents once received their just punishment by being tied up and thrown into the lake off the gallows island near Lindau, is given a new twist. A mysterious case begins for police inspector Annika Wagner (Nurit Hirschfeld) and her colleague Martin Keller (Dominik Maringer). And Robert Anders (Walter Sittler) is also drawn deep into the investigation, as the victim was an old school friend of his.