The action takes place in the late 1920s in Ukraine. The exposure of a counter-revolutionary agent who has infiltrated the Soviet scientific community. The film has survived without the 6th part.
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...
