This Czechoslovakian children’s film takes place during the last days of the Austro-Hungarian empire. The young son of a horse trainer loves nothing more than riding his horse, until he is stricken by polio…
Captain Martin from the police's child department and his colleague Kraus are called to Znojmo to help solve a case regarding stolen toys found in the town's subterranean passages. The members of the local police department are convinced that the thieves are the well-known "customers" from the Znojmo elementary school, pupils Exner and Mandlík. Martin, however, has doubts about these culprits. These doubts grow even stronger after the local self-service shop is robbed and the local tobacco store reports that it is missing a lot of imported cigarettes. Martin questions the children, inspects both shops and searches through the underground.
