Based on an opera by Nikolai Rimsky-Korsakov, which was based on a Russian epic tale of the same name. In the old Russian city of Novgorod, the merchants are feasting in a gorgeous palace and Sadko is bragging that he can bring to their land a sweet-voiced bird of happiness. They laugh at him, but he is offered help by the Ocean King's daughter, who is mesmerized by Sadko's singing and is in love with him. The hero is destined to visit many lands in his search of the bird.

Pioneer Seryozha Emelyanov, who had never been to the steppe before, comes with his father, a chauffeur, for the harvest. The boy's preconceived ideas about farm life being terribly boring, change into love for nature.

The Great Patriotic War is over, but Major Sorokin and Colonel Dobrygin still have a lot to do for their homeland. They must go to West Germany in order to find and return the children who were taken out of the Soviet Union by the Nazis and are now kept in atrocious conditions under the supervision of British intelligence. Former allies want to grow real spies out of their children.

American-dubbed, re-edited version of the 1953 Soviet fantasy film Sadko. Produced by Roger Corman's Filmgroup in 1962, it's shorter by 8 minutes, all music is removed, the names of characters are changed.