A secret trophy obtained in 1942 in the Caucasus could make the Fuhrer's soldiers invincible. The atomic charges created by German scientists in 1944 were capable of sweeping away cities, and new ballistic missiles could reach anywhere in the world and deprive the anti-Hitler coalition of the highest command. And then nothing would stop Hitler from making the Reich great again. After the failure of the Allied landings in Normandy, this scenario began to seem absolutely real. But all three projects were brought to full readiness in Koenigsberg, which was stormed by not quite ordinary fighters - scouts from Captain Filin’s group. Thanks to their feat in 1945, the Nazi plans were thwarted, but the details of the operation were preserved only in closed archives. In 2022, Soviet historian Leonid Zimin, trying to figure out the reason for this injustice, suddenly realizes that he has touched on a secret that mysteriously connects people in a prosperous present and heroic past. A little later, Zimin realizes that he is about to unwittingly rewrite the official history of the Soviet Union! But it’s too late to retreat, Leonid must go to the end, like those scouts in 1945.