Sensationally good … A riveting story, the real-life spooks and spies far more compelling than anything you will see on the screen … history doesn’t come more fascinating than this’ Evening Standard. For over 100 years, the agents of MI5 have defended Britain against enemy subversion. Their work has remained shrouded in secrecy – until now. This first-ever authorized account reveals the British Security Service as never before: its inner workings, its clandestine operations, its failures and its triumphs. ‘Definitive and fascinating … whether reporting on Hitler in the 1930s, the Double-Cross System of the second world war, Zionist terrorism, the atom spies, the Cambridge spies, the so-called Wilson plot or the 1988 shooting of the IRA bombers in Gibraltar, this book is essential reading’ Alan Judd, Spectator. ‘The British Secret Service has opened its archives – and even ‘insiders’ may be in for a surprise … magisterial … extremely readable’ Oleg Gordievsky, The Times