The town of Heiderfeld, where the action takes place, is in the German-speaking area of the Liège province, in the Fagnes region of Belgium.
The Semois, the river "close to the village," in which the body of Driss Assani is found, is in the Luxembourg province, in the Gaumes region, on the opposite side of Belgium.
The local media (radio, newspapers) refer to the Gaumes, whilst the characters alternate between Gaumes and Ardenne, the region between the Fagnes and the Gaumes.
Inspector René Verelst has a Dutch accent. Dutch is one of the official languages of Belgium, but is not spoken in the Gaumes region. That is the region where the river Semois flows, in which the body of Driss Assani is found. Dutch is also not spoken in the Fagnes region, where Heiderfeld is, the town where the action takes place.
Football coach Ronald Vermeiren also has a Dutch accent. It is more likely for a coach to relocate for work than for a policeman.