Synopsis

Erwin Machalik, owner of a renowned pest control company, is found dead. While Chief Inspector Kolbe immediately assumes suicide, Lanner senses murder. From then on, Kolbe Lanner only puts stones in his way and let him run aground. His young colleague Carola Rimschow adores Lanner and is there to help. But both don't have much time to solve the murder. A calamity is already brewing beneath the city, which Machalik announced in a "legacy" before his death: an enormous plague of rats is threatening Berlin. Mayor Koppelberg is desperate. Machalik's brat sons Max and Helmuth, who take over the company after his death, are out of the question as problem solvers. That's when Machalik's clever chief secretary Claire Matthes brings her son Toni Matthes, a top-class exterminator, into play. During their investigations, Lanner and Carola soon track down the mysterious connection MaMMa, which has had the city under control with its secret political and economic machinations for years. And the rats play a not insignificant role in this.