Several scientists create drama around a mysterious black ball.
In July 1942, in the Second World War, the rearguard of the Russian army protects the bridgehead of the Don River against the German army while the retreating Russian troops cross the bridge. While they move back to the Russian territory through the countryside, the soldiers show their companionship, sentiments, fears and heroism to defend their motherland.
A kids from "Armiya Tryasoguzki" are fighting "whites" again.
