Im finsteren Tal

Jana Winter takes over the management of the commissioner in Schleswig and displaces Brauner from Hamm's anger. To avoid the handover, Brauner travels to Bad Gastein. There he is shot on a hike – was he the target of the attack, or did he see something he shouldn't see? Since Brauner has a severe alcohol relapse, he does not remember anything. Investigative Commissioner Franz Robanegg contacts Jana, who is going to Bad Gastein. Near the place where Brauner was shot, the commissioners find a murdered woman – a geologist who wanted to review her husband Thomas Ortlauer's report. Ortlauer apparently had a bad opinion.
Did he kill his wife in a fight over it and make her body disappear in the mountains? The client of the report, Christoph Siewert, is also suspected. Siewert, a wealthy former investment banker, came to Bad Gastein to buy hotels here. Apparently he wanted to push prices down with the fake report. Further investigations lead to a crime that 30 years in the hotel of Peter Kroll. The then maid Doris Höller was raped several times by the patriarch Kroll. At that time she had left the place pregnant and had to release her son for adoption. Upon their return, no one in the village suspects that this lost son is the investor Christoph Siewert.
The past also left its mark on Kroll's family: his daughter Feli, who was then friends with Doris, renounced her patriarchal father. Her brother Georg Kroll, who runs the hotel together with his father, cannot free himself from the dominant father. The investigation shows that Christoph came to Bad Gastein to destroy the place out of revenge for his mother – not to invest in him. Georg Kroll had come behind the intrigue and killed the assessor in an argument. As the investigation approaches Georg, he takes his own life. A final catastrophe begins when Peter Kroll finds his dead son. He makes his way to Doris and her son Christoph –, not knowing who Christoph really is.