In 1943, Robert Oppenheimer, the brilliant, charismatic head of the Manhattan Project, recruited scientists to live as virtual prisoners of the U.S. government on a barren mesa thirty-five miles outside Santa Fe, New Mexico. Los Alamos was a secret city, a primitive barbed-wire-enclosed encampment whose makeshift dormitories and labs housed scientists, their young families, and some of the most advanced scientific equipment in the world. Thousands of men, women and children spent the war years sequestered in this top-secret military facility. They lied to friends and family about where they were going and what they were doing, and then disappeared into the desert. The women came to Los Alamos over the Army's objections. But Oppenheimer insisted it would be the only way to recruit the world-class physicists he needed and keep them reasonably sane and content during the many months - even years - it would take to create this new weapon. Conant shows how the stringent security, lack of privacy, spartan living conditions and loneliness of their isolated mountain hideaway drove some residents to the brink of despair. Yet only a handful gave up and left. Oppenheimer was a leader who, for all his flaws, inspired great devotion, and the author tells the story of the patriotism, sacrifice and triumph of the bomb project through the eyes of a young Santa Fe widow who was one of his first and most loyal recruits.