Summary Patrycja Sikora is found strangled to death on the shore of Lake Constance. When the autopsy shows that she had had sex immediately before the murder, but that rape can be ruled out, the police have a lot of evidence that it was a crime of passion. Ex-boyfriend Nico Nolte reports a consensual break in the relationship, but also that a mysterious stranger recently tried to tell him who Patrycja had an affair with in exchange for money. Paul and Jakob believe that Ralf Kräcker - husband of Patrycja's employer Ines Kräcker - could be the said affair. He could even be a possible murderer. But Ralf receives unexpected backing from his wife Ines. But she is playing her own game. Ines has had private investigator Elke Brandt shadow her husband for weeks. And this Elke is an old acquaintance of Nele. It was also at her instigation that Elke was expelled from the police academy in Hamburg 25 years ago. And Nele quickly realizes that she shouldn't be trusted too much now either. Elke meets with Ralf and makes demands. The police now have to act very quickly.

• Crime