In June 1941, three million German soldiers crossed into the Soviet Union along a front stretching from the Baltic to the Black Sea, the largest invasion force in history up to that point. This film traces how Wehrmacht panzer columns tore through Soviet defenses in weeks, encircling entire armies at Minsk, Smolensk, and Kiev, and pushing to within sight of Moscow's suburbs by autumn. Archival footage and maps chart the German high command's confidence that the USSR would collapse within months, and the miscalculations, stretched supply lines, the onset of winter, Stalin's reserves from Siberia, that turned momentum against them at the gates of the capital. Historians walk through the strategic decisions on both sides, from Hitler's diversion toward Kiev to Zhukov's counteroffensive in December 1941, explaining why a campaign built for a swift knockout blow instead became the opening chapter of a four-year war of attrition on the Eastern Front. The film treats Barbarossa as the hinge on which the entire war turned.