In a New Mexico snow storm, four men cross a barbed-wire fence at Stallion Gate to select a test site for the first atomic weapon. They are Oppenheimer, the physicist; Groves, the general; Fuchs, the spy. The fourth man is Sergeant Joe Peña, a hero, informer, fighter, musician, Indian. These four men—and a cast of soldiers, roughnecks and scientists—will change history forever.