1939-1945 20thcentury adventure allies atomic-bomb atomicbomb britain churchill commandooperations commandos commandotroops covert-operations espionage germany guerrilla-warfare heavy-water heroes historical-nonfiction history hydroelectric-power-plant intelligence military-history nazi-germany nazi-occupation nonfiction norway norwegian-history norwegian-resistance norwegian-saboteurs oss resistance sabotage science-and-technology secret-agents secret-mission secret-missions strategy technology true-story underground-resistance undergroundmovements war weapons world-war-ii worldwar worldwar(1939-1945)