On a hot day in July, the body of a 16-year-old girl is pulled from the river Main near Frankfurt. She has been brutally attacked and murdered, but no one seems to miss her and no one seems to know who she is. Investigations lead to a rural children's home in the mountains, and to a TV presenter whose research took her too close to the wrong people. As investigators Pia Kirchhoff and Oliver von Bodenstein dig deeper, they uncover a pit of evil and cruelty in the midst of a middle class idyll. And then the case gets personal ...