This book contains the transcripts of interviews with eight leading atomic scientists and the former head of the Manhattan Project, focusing on their work during World War II. Among those scientists are two who worked on the German atomic project, Werner Heisenberg and Paul Hartek, one who worked on nuclear development in France, Lew Kowarski, and five who worked in the United States: Aristid von Grosse, C. E. Larson, A. H. Snell, W. A. Arnold, and K. W. Bahler. The interviews, recorded in the late 1960s and early 1970s, cover not only their war work, but also their lives and other scientific work.