After a triple murder in a small village in the Jura, detective Rosa Wilder has to deal with a deeply saddened village community. The only witness to the drama is in great danger.

Rosa and her French colleague Jamel Jaoui are on the trail of the Jura drug mafia; Simon Kägi, the prime witness, finds his life in danger since he has hidden money belonging to the mafia.

Rosa and colleagues search for Simon and Adelina, whose lives are at risk. Village policeman Leo Mott faces pressure due to his affair with a victim. Manfred Kägi's lead uncovers a connection to his family's past.

The noose tightens around Mott, driving him to a desperate act. Rosa reveals to Manfred Kägi that he's her son's father. A clue leads them to a serial rapist's trail. Could this person be behind the triple murder?

Charles Mulliger is arrested, and Susann uses a ruse to get the arsonist to talk. Rosa and Kägi arrest a suspected serial rapist, who makes a confession.

Rosa Wilder is hard on the heels of a serial rapist and finally manages to resolve a triple murder. The crimes from the past are also connected to it. The revelations about the Thallingen tragedy are devastating news for the local families.