Tóm tắt nội dung: The gripping inside story of the last unknown realm of the British secret service: GCHQ (Government Communication Headquarters). GCHQ is the successor to the famous Bletchley Park wartime code-breaking organisation and is the largest and most secretive intelligence organisation in the country. During the war, it commanded more staff than MI5 and MI6 combined and has produced a number of intelligence triumphs, as well as some notable failures. Since the end of the Cold War, it has played a pivotal...