At the end of the war ten German scientists were interned in a country house named Farm Hall in Britain. With one exception, all had worked on the wartime research project on the economic and military applications of nuclear fission. There were microphones hidden in the walls and the Germans’ conversations were recorded, excerpted, translated, and transcribed, including in particular their reactions to the surprising and shocking news of Hiroshima. The Germans discussed four basic questions among themselves: Did they know how to build an atomic bomb? Could the Germans have built these weapons? Did the Germans try to make atomic bombs? Had they been Nazis?