The film is set in the city of Krasnodon (Sorokyne) in 1942 during the Nazi occupation of Ukrainian SSR (now Luhansk Oblast of Ukraine). Local teenagers are organizing the underground resistance. The teens manage to outsmart the Nazis in their fight. They blow up the Nazi recruitment offices. Their activity lifts the spirits of the surviving citizens. They organize other school-friends in the groups of five to help the citizens in their struggle for survival. Their courage helps many others to survive.