The film is based on authentic events that took place in 1957 in Kursk. Fifteen years after the war, the sappers will have to clear away the ammunition depot left by the German's. The town rebuilt with such difficulty is under threat of explosion...

The Soviet boys, Vadik and Yura, together with the mischievous little girl Tosha, are children with a kind heart and good life philosophy. One day they find money on the street, which must be returned to the owner without fail. But where to find an inattentive citizen who has lost not only money, but also a booklet with quite important information. So, begins the time of exciting adventures, breathtaking moments, high-quality humor and instructive-entertaining ideological line.