A professor of architecture at Cambridge University, Marcial Echenique, recently became curious when he found wiring concealed under the floorboards of his country mansion, Farm Hall in Godmanchester, Cambridgeshire. The mansion had an astonishing past as an MI6 staging post for some of the most daring secret operations of the Second World War. But in April 1945, Farm Hall was to play an even more astounding role, as a 'country club' for ten of Germany's top nuclear physicists after they had been captured in Germany and secretly flown back to England in a daring raid code-named Operation Big. Every word they uttered was bugged by MI6 eavesdroppers using the wires found by the professor. After the dropping of the bomb these men would claim they could have developed it for the Third Reich but did not 'for the greater good of mankind'. Most believe this to be a deception. But was there an even greater deception? Were they captured not to stop Hitler, but to stop Stalin? Did the US drop the bomb not as a show of power to the Japanese, but to the Soviets? Colin Brown guides us through a world of espionage, scientific discovery and questions of morality as he reveals the extraordinary truth surrounding Hitler's atomic bomb.