Mid-fifties Anne Marie Fuchs lives modestly and withdrawn in Düsseldorf. When a murder happens, it becomes clear that the inconspicuous lady, who is always in short supply, seems to be an absolute investigator with a razor-sharp mind. No wonder, because Anne Marie Fuchs is a former East German spy, especially one who still has a bill from her active time open.

During their investigation into a toxic waste scandal, Yousseff and Anne Marie Fuchs' client are found dead, and the two detectives find themselves in a life-threatening situation.

Anne Marie Fuchs' ex-husband Konrad Gelden was shot dead in his villa. This shatters the private detective's hope of solving the riddle of the disappearance of her son Florian. Almost thirty years ago, he was kidnapped as a boy to punish Anne for leaving the Stasi. When Anne's business partner Youssef receives a new order, the tide turns.

Youssef's cousin Jamila is said to be forced into marriage, but at the henna evening the German groom is disfigured with baseball bats. Soon afterwards, Youssef and his fellow detective Anne Fuchs find Jamila's secret lover - dead.

During a dress rehearsal for a fashion show, the model Nastja believes to have seen a murder. The victim is her friend Kira, but there is no trace of her. The detectives Anne Marie Fuchs and Youssef el Kilali, however, soon come across the body of the young woman in a clothes trolley belonging to the fashion company and begin to investigate.

The wife of the Düsseldorf Police Council Rainer Bachmann is kidnapped. While trying to save his mother Monika, the adult son is shot dead. His widow Nicola desperately seeks support.

Youssef's niece Saida finds her boyfriend, the young doctor Hagen Hoffmann, slain in their shared apartment. Based on the victim's computer activities, the police assume that the crime was committed in a drug environment.

Anne Marie Fuchs investigates for the first time on behalf of the Federal Office for the Protection of the Constitution. Together with her fellow detective Youssef El Kilali , the experienced team sets out to solve two murders. But can they also stop the espionage attack on the Federal Office for the Protection of the Constitution?

High school graduate Max Höfel arrives at the Fuchs & Kilali detective agency distraught: his girlfriend Leonie has been run over by a car and the police believe it was a hit-and-run accident. Max, on the other hand, believes it was murder and hires the two detectives to find the culprit. Leonie used to work in Max's uncle Lukas Bender's amusement arcade. Anne and Youssef find out that dirty mafia money is laundered there. When a large sum of money is found in Leonie's estate, Inspector Eisner is also convinced that a violent crime has been committed. Did Leonie want to expose her employer - is that why she had to die? Max's mother Marina protects her brother Lukas. He would never be capable of murder! A deep rift runs through the Höfel family, behind whose façade Anne and Youssef have to look in order to finally solve the case.