After Hannah Zeiler has not yet returned from her motorcycle vacation, Micha Oberländer (Matthias Koeberlin) has to deal with Austrian Inspector Luisa Hoffmann (Alina Fritsch) and at the same time investigate the intimate web of an only seemingly conventional family.
A man's lifeless body is found in the woods near Lake Constance, posing a sinister mystery for the duo. Photos of the family of Professor Lambeck (Heikko Deutschmann), head of the psychiatric clinic at Lake Constance, are found in the makeshift quarters of the dead man, with the eyes of each family member gouged out.
When the deaf girl Trischa (Kea Kraussau), who seems to have been watching the investigators in the forest, can no longer be found, the circle of suspects is further expanded.
Neither Lambeck himself nor his wife, their daughter or her boyfriend, claim to have known the dead man.
But why did the murder victim photograph the family? What did the dead man want to take revenge on the family for?
And does Trischa pose a threat to the Lambeck family, or was she just a witness and could be the next victim?