Eight-year old Dominique has a name-day. Her parents have a gift for her, but only give it to her in the evening, when everybody has come home from work. Then she darts out, where her girlfriends are already waiting for her.
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.
