About a merry, smart boy Tom Soyer, that, testing, as him it seemed to, all facilities, to be good, decided nevertheless to go away from home and become a marine robber.

To help out his friend Lenya, Yura steals a Stradivarius violin belonging to the professor from his grandfather, a violin maker. Having learned about everything, the professor begins to study with the talented Lenya. Circus performers persuade Lenya to give up the violin and perform in the circus...