The film is set in July 1942 during The Great Patriotic War. Part of the Red Army leaves the mining town Krasnodon. After that, the city gets occupied by the German troops. Enemy machines destroy their path and members of the Komsomol group are forced to return home. In response to the atrocities of the invaders, the young Komsomol members, who are former students, create an underground Anti-fascism Komsomol organization Young Guard (Soviet resistance). This organization leads a covert war against the occupation forces; young men spread antifascist leaflets, free a group of Red Army prisoners, burn the German stock exchange, thus saving their countrymen from being sent to work in Germany. On the day of the Red October anniversary, the young guards hang Flag of the Soviet Union.