Near the end of World War 2, the Allied forces arrested ten German scientists who were thought to have worked on Nazi Germany's nuclear program and housed them together at a bugged country house called Farm Hall in Godmanchester, near Cambridge, England. For six months from July 1945 to January 1946, a team of operators listened to and recorded their conversation in the hope that the scientists would divulge information that would help the Allied determine whether Germany had worked out the intricate details needed for making a working nuclear bomb, and if not, how close they got into making one. The operation was nicknamed Epsilon.

Farm Hall, where the ten German scientists were incarcerated.