In the course of its war for world domination & a projected racial utopia, Hitler's government committed monstrous crimes. As defeat neared, the Third Reich's officials tried to destroy all the physical & documentary evidence about their murder of millions. They did not fully succeed, but huge gaps in the historical record have made it hard for us to reconstruct how they planned the Holocaust. Great Britain already had some of the evidence, however, for all along its intelligence services had been intercepting, decoding, analyzing, & circulating many German police radio messages & some from the SS. Yet this critical evidence was sealed away - marked "Most Secret," "To be Kept under Lock & Key," & "Never to be Removed from this Office" - & it has only now reappeared. Integrating this new evidence with the known sources, the author examines how Germany's leaders brought about the Holocaust-& when. He assesses the British & American suppression of information about Nazi killings, & the tensions between the two powers over how to respond. His absorbing work concludes with an examination of the consequences (including the failure to punish many known war criminals) of keeping this information secret for so many decades.