The Nazis were on the point of making an atomic bomb, a bomb they would not hesitate to drop on London. All they needed to perfect the device was an adequate supply of 'heavy water' and this they manufactured at Norsk Hydro, a vital plant hidden away in a near-impenetrable ravine in German-occupied Norway. In the winter of 1942-3 it became clear that there was almost enough 'heavy water' ready to be shipped to Hamburg. Churchill and the British Cabinet were desperately worried. The plant had to be sabotaged at all costs.
This book tells the story of the eleven men, all Norwegians, but trained by and under the direction of the Special Operations Executive in Britain, who parachuted into the snow-covered highlands of their homeland with the mission to destroy the plant, and thereby perhaps to save western civilisation. Living off the land amongst the unspeakable conditions of the northern winter, they endured terrible hardships, but never flinched from carrying through their historic task.