Did German nuclear scientists in World War II deliberately derail their atomic bomb project? Were there factors beyond their control? Or were they simply beaten to it by the Americans? Operation Epsilon: The Farm Hall Transcripts throws some light on these questions, which have exercised the minds of scientists and historians for 50 years. It contains information which has been classified top secret since 1945 and only recently declassified after years of pressure from scientists and historians. In Germany at the end of the war, Anglo-American Intelligence rounded up the most well-known nuclear scientists and transferred them to Farm Hall, a country house in Cambridgeshire. They were to be guests there for six months. Unknown to the scientists, Farm Hall was bugged and their conversation recorded, transcribed and translated. This book publishes these translated transcripts for the first time. The scientists were still captive when the atomic bomb was dropped on Hiroshima. Their reactions to the news ranged from disbelief to the contemplation of suicide. The ensuing discussions are transcribed in this book, giving a valuable insight into the state of knowledge of the Germans during the war. The transcripts also reveal much about the states of mind of these men. Family worries, personal ambition, political beliefs, thoughts of escape and their escalating frustration at their continued captivity are all graphically depicted in their conversations. For instance, one was awarded a Nobel prize while in captivity, but he was not permitted to receive it in person at the time. The background to the transcripts in described in the introduction by Professor Sir Charles Frank FRS, Sir Charles worked in German laboratories before the war, and then for British Intelligence during the war on the Farm Hall project. Sir Charles has also re-translated a section containing important technical detail as the original translation was inaccurate. The original German transcription for this section is also reproduced for the historical record.