Torsten Hanke, the murderer of Dennis Bayer, is shot in front of the courthouse after his acquittal. Vera Lanz is quickly convinced: This was the act of a professional killer. But who wants to avenge Dennis' death and has the wherewithal to afford a professional? The investigations lead Vera Lanz and her colleagues Jan Trompeter and Paul Böhmer to the red-light district of the Bavarian metropolis. Böhmer's interrogation of Dennis' mother Liane Bayer provides a crucial clue. Dennis trained at a boxing club that Böhmer is not unfamiliar with. His physical investigations are not without results. Dennis' father, kept secret by Liane for a long time, is said to be Franko Holzinger, a well-known Munich milieu.
Did Holzinger hire the killer to avenge his son? But the DNA test also has a surprise in store for Holzinger: He is not Dennis's biological father. When Böhmer examines Liane Bayer's family background more closely, it quickly becomes clear to him that there must be a far more dangerous client behind Holzinger: Anton Slimemann, Liane's father, who knows more about Böhmer's past than the policeman would like. Vera Lanz and Jan Trompeter notice that Böhmer is beginning to investigate on his own. Does Böhmer still know which side he is on?