During the Second World War, Allied intelligence became convinced that German scientists were racing toward an atomic bomb, a fear that shaped some of the war's most daring covert operations. This film from the Timeline series traces the effort to stop Werner Heisenberg's nuclear research program, focusing on the sabotage raids against the Vemork heavy water plant in Norway, a facility crucial to any German attempt at reactor design. Commandos parachute into occupied Norwegian terrain, ski through winter conditions, and plant charges against a heavily guarded industrial target, while intelligence officers back in Britain and America try to work out how close German physicists actually came to success. The film draws on wartime archival footage, expert interviews, and reenactments to reconstruct both the Allied paranoia and the reality of Germany's fractured, underfunded nuclear effort. It closes on the postwar reckoning, when captured German scientists learn just how far behind the Manhattan Project they had fallen.