Every Tenth 1984

Five Red Army soldiers, who found themselves in the rear of the Kolchak troops, captured an enemy armored car and captured an intelligence officer. From him they learn that soon a steamer with weapons and ammunition for the upcoming white counteroffensive is due to pass along the river. How to stop the ship, capture it, and then transport such a valuable cargo through ambushes and cordons of Kolchak troops entrenched on both sides of the river?..