Book excerpt: From the internationally acclaimed, best-selling author of Hunting Eichmann and The Perfect Mile, a World War II spy adventure set in Norway that draws on top-secret documents and memoirs of the saboteurs. In 1942, the Nazis were racing to complete the first atomic bomb. All they needed was a single, incredibly rare ingredient: heavy water, which was produced solely at Norway’s Vemork plant. Under threat of death, Vemork’s engineers pushed production into overdrive. If the Allies could not destroy the plant, they feared the Nazis would soon be in possession of the most dangerous weapon the world had ever seen. But how would the Allied forces reach the castle fortress, set on a precipitous gorge in one of the coldest, most inhospitable places on earth? Based on a trove of top-secret documents and never-before-seen diaries and letters of the saboteurs, The Winter Fortress is an arresting chronicle of a brilliant scientist, a band of spies on skis, perilous survival in the wild, Gestapo manhunts, and a last-minute operation that would alter the course of the war. “Riveting and poignant . . . The Winter Fortress metamorphoses from engrossing history into a smashing thriller . . . Mr. Bascomb’s research and, especially, his storytelling skills are first-rate.”—Wall Street Journal