The picture recounts the first days of the Great Patriotic War, when in the turmoil of the retreat of Soviet troops, there remains a forgotten artillery formation under Brest under the command of Lieutenant Gusev, yesterday's graduate of the military school, who arrived in the location of his unit just a day before the war began. Surprisingly surviving the bombing, Gusev and his comrades find themselves in the rear of German troops. Armed with a 45-caliber anti-tank gun, the young fighters decide to break through to the Soviet troops, while the front continues to retreat further and further.