The film tells the story of three young Red Army soldiers fighting against Makhno gangs. In the 20-ies of the last century, during the civil war, in one of the villages of Ukraine lives a railway worker Petrov, who has two children Misha and Dunyasha. The children are passionate readers of Voinich and Cooper novels. Unexpectedly, the village is attacked by Makhno’s band. Petrov dies in the fight. Before his death, he asks his children to fight against bandits and take revenge. Misha and Duniasha make promise. In the children’s imagination, the romance of adventure novels is connected to their reality. They realize what is the goal of their ultimate fight. In the Ukrainian steppes Misha and Dunyasha come across black Tom Jackson, who becomes their loyal friend. After many misadventures three friends join Budyonny's army, where they are enlisted as spies. Courage, shrewdness and devotion often save little spies from war ordeals. Eventually they capture Makhno himself and take him to Budyonny’s camp. Misha, Dunyasha and Tom Jackson are awarded for bravery and combat service.