This case is personal for Klooz: Why are his favorite chewing gums disappearing from Olga's kiosk? The little detective immediately starts the investigation. Could "Fidis" have something to do with the successive thefts? Klooz follows the clues... and soon finds himself in a very difficult position.

An exciting series for young readers, featuring a nine-year-old boy who has nothing to envy from the heroes of classic detective novels.

The series was awarded the Hansjorg-Martin-Preis in 2006, the most important German award for authors of children's and teen detective books.