The first month of bloody battles of the Second World War. The Nazis are trying to seize the Ukrainian capital. After calculating some data, they understand that now is the best time to "put the squeeze" of the city. The Germans are preparing a military operation, but the Soviet troops still have a chance and they have to take advantage of it. The only hope for the surrounded troops is the Armored Train «N56». Its mission is to stop the advance of the Nazis and break the siege ring, creating a corridor for saving Russian soldiers.