Novye priklyucheniya neulovimykh (1968)

The action takes place in 1920, during the Russian Civil War. The four young scout heroes - "The Elusive Avengers" from the previous film - when returning from the next task, they manage to knock out a flying White Guard airplane. In the tablet of the pilot detained during the fall, were found documents indicating that the White Guards built secret defensive fortifications in the Crimea.