J.C. Masterman was chairman of the Double-Cross Committee at the height of World War Two. This is his account of the double agents, deception and counter-espionage which were key to the victory of D-Day.

Written as an official report for MI5 in 1945, originally published with the permission of the British Government over twenty years later,The Double-Cross Systemdetails the Allied handling of enemy agents and the British infiltration of Nazi spy-rings.

Telling the stories of the agents codenamed Zigzag, Tricycle, Garbo and Snow, Masterman also tells the story of a triumphant operation in the Second World Wars intelligence effort.

John Masterman spent the Great War, despite one escape attempt, interned in Berlin. After leaving Christ Church in March 1940 he was commissioned into the Intelligence Corps. Fluent in German, he attended the interrogation course at Swanage before being posted to the War Office as secretary to the committee which investigated the evacuation from Dunkirk. On completing its report Masterman was transferred to the Security Service working in the counter-espionage division. In 1941 he was assigned the taqsk of debriefing Dusko Popov, and it was this remarkable encounter between one of the Abwehrs star agents and his M.I.5 handler that led to the creation of the Twenty Committee, the body created to supervise the conduct of double agent operations. Masterman chaired weekly meetings of the Double Cross Committee, as it became known, before he was invited to write an account of its activities at the conclusion of the war. Twenty-seven years later he revealed to his former employers that he had retained a copy of this manuscript, and intended to publish it in America, an experience described in his autobiography,On the Chariot Wheel, released two years before his death, in June 1977.

Nigel West was educated in France and at London University. He worked as researcher before joining the BBC where he contributed to numerous television documentaries, includingSpy!, on which he based his first book, andEscape!. While still working for the BBC he was commissioned to write the wartime history of the Security Service,M.I.5, followed byM.I.6: British Intelligence Service Operations 1909 45andA Matter of Trust: M.I.5 1945 72, the subject of an Attorney-Generals injunction. His other books includeUnreliable Witness: Espionage Myths of World War II,Molehunt,GARBO, GCHQ: The Secret Wireless War,The Friends: Britains Postwar Secret Intelligence Operations,Games of Intelligence,Secret WarL The Story of SOE,The IllegalsandSeven Spies Who Changed the World. Most recently he has compiled two anthologies,The Faber Book of EspionageandThe Faber Book of Treachery. He is married with two children and lives in London and Devon and is the European Editor of a monthly journal, theWorld Intelligence Review.