For better or worse, Navy captain William S. ""Deak"" Parsons made the atomic bomb happen. As ordnance chief and associate director at Los Alamos, Parsons turned the scientists' nuclear creation into a practical weapon. As weaponeer, he completed the assembly of ""Little Boy"" during the flight to Hiroshima. As bomb commander, he approved the release of the bomb that forever changed the world. Yet over the past fifty years only fragments of his story have appeared, in part because of his own self-effacement and the nation's demand for secrecy. Based on recently declassified Manhattan Project documents, including Parsons's logs and other untapped sources, the book offers an unvarnished account of this unsung hero and his involvement in some of the greatest scientific advances of the twentieth century. Described by the author as a naval officer with the heart of a sailor and the searching mind of a scientist, Parsons was the first officer to recognize radar's full potential, the military's leader in the development of the proximity fuse, and the warrior who took both that fuse and the atom bomb--the two most revolutionary weapons of World War II--into combat. Al Christman credits the success of many programs to Parsons's battles against bureaucratic inertia, his championing of new ideas, and his charismatic but low-key leadership. His influence continued even after the war when the so-called ""Atomic Admiral"" helped establish the Navy's postwar nuclear policies and advance the scientific developments that are at the heart of today's sea service. Filled with human drama set against a background of national peril, this book tells a fascinating story that will draw in even the nontechnical reader.