1939-1945 20thcentury adventure allies atomic-bomb atomicbomb commandooperations commandotroops espionage germany heavy-water historical-nonfiction history hydroelectric-power-plant military-history nazi-germany nazi-occupation norway norwegian-history norwegian-resistance norwegian-saboteurs sabotage science-and-technology secret-mission special-operations-executive technology true-story undergroundmovements war world-war-ii worldwar worldwar(1939-1945)