Professor Gromov constructs a robot called Electronic, which looks exactly like Sergey Syroezhkibn, a 6-grader from one of Odessa (USSR) schools. The robot also acts a lot like a human, and its dream is to become a real man. Electronic escapes from the professor's lab and accidentally meets Sergey, his prototype. Meanwhile, a gang lead by Stump is trying to kidnap Electronic to make him steal pictures from museums. For this purpose they send their hitman Urrie.

The action of the movie takes place during the Bolshevik coup. A fifteen-year-old teenager from the province, becoming a fighter of the Red Army, successfully passes the beginning of a great path of the school of “courage“...

The hard days of August 1941. Enemy troops approached Zaporozhye, the island of Khortitsa was captured, and the Nazis shelled the city from its high banks. Our troops sought to recapture this bridgehead at all costs. Schoolchildren - fighters of the "Young Chapaevets" detachment - helped the Soviet soldiers.