October 20, 1944, Belgrade was liberated by Red Army and Tito's partisans. But the capital of Yugoslavia is still fraught with danger - retreating aggressor mined the city . A special partisan squad goes into underground maze of tunnels to find and disarm explosives which are still guarded by SS special forces.

The story of the hero of the Soviet Union, Manshuk Mametova, machine-gunner of the 21st Guards Rifle Division of the 3rd shock army of the Kalinin Front, the guards sergeant in charge. The first woman awarded the title of Hero of the Soviet Union for bravery. The film recreates the past and shows a day of combat life Manshuk and her comrades, who took unequal battle with German tanks.