The events take place in 1919 in Bessarabia.

On the eve of the New Year, a Belgian plane carrying a group of Antarctic researchers crashes in the area of the Pearl Mountains. Only the Soviet expedition responds to their call for help. For several days, Soviet pilots, despite the weather conditions and risking their own lives, set out in search of the Belgians...

An officer accidentally leaks information about the first test of a new aircraft model. When spies get hold of this classified information, the development of the new airplane is under threat.

The movie is based on the the same name novel of the Nobel Prize In Literature Winner Mikhail Sholokhov. The action is taken place in 20-30-s years of the XX century in the Russian countryside going through an uneasy process of collectivization.