Six years after his departure as crime scene commissioner at the Duisburg Criminal Investigation Department, the police are asking private citizen Horst Schimanski (Götz George) for help. So he leaves his houseboat in Belgium and his steady girlfriend (yes, the man has just grown old) Marie-Claire (Denise Virieux) repeatedly leaves temporarily to catch the bad guys. Sometimes he does so against the will of the police or just gets hired as a private detective or bodyguard. After the death of his partner Thanner, Schimanski is now supported in his investigations by the young policeman Tobias Schrader (Steffen Wink). However, he leaves Schimi alone at the end of 1999 after episode 6, and in the next episode, almost a year later, Hänschen (Chiem van Houweninge) is back, Schimanski's old colleague from crime scene times; Thomas Hunger (Julian Weigend) becomes Schimi's new ace.