The renowned physicist Emilio Segre (1905-1989) left his memoirs to be published posthumously because, he said, 'I tell the truth the way it was and not the way many of my colleagues wish it had been'. This compelling autobiography offers a personal account of his fascinating life as well as candid portraits of some of this century's most important scientists, such as Enrico Fermi, E. O. Lawrence, and Robert Oppenheimer. Born in Italy to a well-to-do Jewish family, Segre showed early signs of scientific genius - at age seven he began a notebook of physics experiments. He became Fermi's first graduate student in 1928 and contributed to the discovery of slow neutrons, and later was appointed director of the physics laboratory at the University of Palermo. While visiting the Radiation Laboratory at Berkeley in 1938, he learned that he had been dismissed from his Palermo post by Mussolini's Fascist regime. Lawrence then hired him to work on the cyclotron at Berkeley with Luis Alvarez, Edwin McMillan, and Glenn Seaborg. Segre was one of the first to join Oppenheimer at Los Alamos, where he became a group leader on the Manhattan Project. His account of that mysterious enclave of scientists, all working feverishly to develop the atomic bomb before the Nazis did, includes his description of the first explosion at Alamogordo. Segre writes movingly of the personal devastation wrought by the Nazis, his struggles with fellow scientists, and his love of nature. His book offers an intimate glimpse into a bygone era as well as a unique perspective on some of the most important scientific developments of this century.