Fourteen-year-old Wastl, who wants to publish an article about police work in his school newspaper, accompanies Hubert and Girwidz during a speed check. When Riedl stops a speeding prototype car, the investigators discover the body of Rosalie Motz inside. Dr. Fuchs determines that she was murdered.

When Hubert and Girwidz visit her father, Ferdinand Motz, they learn that Rosalie had been a test driver for the start-up of Gernot Schirrmeister—who proves to be anything but cooperative. He is mainly concerned with getting his prototype back in order to protect the technical secrets it contains. These very secrets also interest journalist Titus Eggert. When the officers discover that he knew the victim and had even spent a night in the mountains with her shortly before her death, he becomes highly suspicious.

Meanwhile, Tom Burgmüller has written a perhaps overly candid article for the school newspaper about Hubert and Girwidz's unorthodox investigative methods. Normally, this might not concern station chief Sabine Kaiser—if Tom weren't the police commissioner's nephew…