The original history of Bletchley Park's Hut 6 was considered so sensitive, it was only declassified in June 2006. For the first time the wider public can read the story of Bletchley Park's epic battle with the Enigma-enciphered messages of the German Army and Air Force, as written by the codebreakers and edited by John Jackson. This momentous struggle is told anonymously by the men and women working in Hut 6 at Bletchley Park, who recorded their experiences in a top secret report at the end of World War 2. Where the German forces went the Enigma machine went with them. The daily changing cipher keys and the continuous security improvements put a continual strain on the quiet heroes of Bletchley Park. This specially edited version of the original three volumes, which includes all of the volume on cryptography, is a lasting tribute to their unrelenting pursuit of the innermost secrets of the Nazi war machine and to their genius in overcoming all the odds.