A dead man lies in a Duisburg bus - apparently the accidental victim of a stabbing. The murdered man was the owner of a dance studio that he ran together with his wife, Manuela Prinz.
Thanner is annoyed: While he has to do the dirty work for the police - he has to identify the body of a prostitute - Schimanski is reopening a case that he, Thanner, closed long ago. And Thanner knows why: Ilona Vogtländer, daughter of Rolf Vogtländer, who is accused of murdering his wife Eva, is far too beautiful for Schimanski to resist.
Schimanski and Thanner are confronted with a case that happened a long time ago and that they were unable to solve: in 1978, one of the perpetrators was seriously injured during a bank robbery and was then executed in the bank by the leader of the gang. The perpetrators managed to escape - except for the Pole Zbiginiew Pawlak, who waited next to his dead brother until the police arrived. During the subsequent investigation, Pawlak was unable to say a word. The press then nicknamed him "Moltke", which he kept even during his prison sentence because he remained stubbornly silent.