Hitler's downfall began well before the official end of the war in 1945. It was exactly on 22nd June 1941, when Hitler launched the largest military offensive in history against the Soviet Union: Operation Barbarossa. By opening this eastern front, the Führer, blinded by his firepower, signed his own death sentence. This episode relates, through archives and re-enacted scenes from historical documents, this fateful day. Why did Hitler open a second front after always saying he wouldn't? Why did he suddenly attack the Soviet Union, which did not want to be an obstacle to its enterprises on the west and south fronts? And, why did Stalin foresee the attack?