Guy Liddell was the Director of MI.5's counter-espionage B Division, and from September 1939 to May 1945 he maintained a personal diary. Within its pages, details of virtually every important event that had any intelligence significance during the Second World War were recorded. These diaries have recently been declassified and published, being edited by Nigel West. It was during this editorial process that Mr West sought to investigate Guy Liddell's activities beyond the end of the Second World War, resulting in the present volume. The diaries themselves reveal many disturbing secrets. Amongst these are the contents of a cache of German documents that the SS were supposed to burn, but which were buried instead. When these were recovered, the British authorities went to considerable lengths to keep their contents from being revealed, for they demonstrated the activities of the Duke of Windsor during the crucial period in 1940-41, when Britain stood alone, threatened with invasion. They showed that the Duke was willing to act as an intermediary between Britain and Germany and was ready to fly back from the Bahamas to 'intervene' if required. It was implied that he was prepared to be restored to the throne if the situation required it. Guy Liddell continued to work for MI.5 after the war and it is this period that is the main focus of this present book, with further declassification of files from this period enabling Nigel West to expose the inner working of MI5 at the height of the Cold War. This study provides an intriguing insight into the day-to-day activities of a group of men and women dedicated to detecting and interdicting sabotage, subversion and espionage. Liddell rose to the position of Deputy Director of MI.5, and it was expected that he would become the next Director. But he worked with Kim Philby, employed Anthony Blunt as his personal assistant and socialised with Burgess and Maclean. His failure to spot these men as traitors led to his retirement from the Secret Services in 1953. Nevertheless, Guy Liddell he was probably the single most influential British intelligence officer of his era.