The dropping of the first atomic bomb on Hiroshima on 6 August 1945 announced to the world that nuclear weapons were no longer the stuff of imagination. From its inception in 1941, the Manhattan Project saw some of the world's best physicists and engineers develop the most potent armament known to man.

In this book Al Cimino explains the events that led to President Roosevelt sanctioning the development of the bomb and recounts the dramatic story of how a gifted and often conflicted group of people, including Oppenheimer, Enrico Fermi, and Leo Szilard, devoted themselves to unlocking the secrets of nuclear fission.