The action takes place during the civil war in Ukraine. Sergushin, an injured Red Army commissioner, is hiding in Mandjoura's house, but is reported to the Whites by a child, Kotka Grigorenko. Sergushin is discovered and shot in front of children who swear to avenge the commissioner. A few years later, they will have the opportunity to denounce the treachery of Kotka Grigorenko who returns from the foreigner where he had emigrated.