Kurt Nordstrum, an engineer in Oslo, puts his life aside to take up arms against the Germans as part of the Norwegian resistance. After the loss of his fiancée, his outfit whittled to shreds, he commandeers a coastal steamer and escapes to England to transmit secret evidence of the Nazis's progress towards an atomic bomb at an isolated factory in Norway. There, he joins a team of dedicated Norwegians in training in the Scottish Highlands for a mission...