The owner of a bicycle shop is found dead in his store by his girlfriend Steffi and his employee Tom Lehnert. Steffi's ex-boyfriend quickly comes under suspicion by Beissl and Jerry. He clearly hasn't gotten over the breakup and has been stalking her.

The deceased also owed a good friend a lot of money, which the friend demanded back shortly before his death. But it is only when the detectives take a closer look at Tom Lehnert's past that they track down the murderer.

Doris Renz, divorce lawyer and soloist in a well-known amateur choir, is found murdered. It quickly becomes clear that the victim was rather unpopular in the choir, and Jerry even suspects bullying. The choir member Nina Golling in particular had a bone to pick with the deceased, who had been the choir's soloist for years. Did she eliminate her rival?

But other choir members also had a motive to kill the woman. Were they driven to commit the crime by the agitation? It is thanks in no small part to Johanna that the detectives' attention is drawn to a new lead, which ultimately leads to the solution of the case.