Those who attended the Nuremberg Trials could never quite satisfy themselves on the question of whether the defendants were truly mentally normal. Could it be that they were all maniacs, psychopaths, deranged sadists? And sure enough there were those among the staff of the International Military Tribunal who had to decide this on a professional level – psychiatrists and psychologists. There were three in particular who played a vital role in assessing the mental state of the criminals from whose acts the civilised world shrank in disgust. They were all American and two of them were Jewish and their experiences, which made them international stars, haunted them to their dying day. They were Douglas Kelley, Gustave Gilbert and Leon Goldensohn. Day after day they explored the paradoxes of Nazi psychology and grappled with the subconscious of history's greatest villains. But the conclusions drawn after numerous tests and extensive examinations dismayed even the experts.