This television series takes place during the first Czechoslovak Republic (1918 1939). The stories make use of the historical existence of an investigative constabulary unit (the precursors of today`s detectives) and its actual cases. At the time, the constables were a key organization, helping to investigate and solve criminal activities in mainly the countryside and small towns. The lead characters in the series are constables from the Brno investigative unit who solve crime as part of their everyday experience from tragic and violent felonies to banal and even slightly humorous cases of petty thievery and other wrongdoing.