Ben Macintyre discusses Agent Zigzag - his bestselling book on the true story of a professional criminal named Eddie Chapman, a successful British double agent who infiltrated the Nazi intelligence services during World War II.

A notorious safe-breaker before the war, Chapman duped the Germans so successfully that he was awarded their highest decoration, the Iron Cross. He remains the only British citizen ever to win one.

His story is one of chance and charm. Recruited as a spy whilst serving time in a Jersey jail, Chapman persuaded his German spy-masters that he was serving the Third Reich, but when they parachuted him into Norfolk in 1944 he delivered himself immediately to MI5. Because of the advanced and highly secretive code breaking at Bletchley Park, MI5 were expecting this unknown spy, with his German name of Agent Fritz. Reflecting his ambivalent status, his new British handlers called him Agent Zigzag.

Ben Macintyre says that Chapman's missions of sabotage and feeding false messages back to Germany were instrumental in saving hundreds of lives, as well as averting the V1 bombers from St Paul's Cathedral.

James Naughtie presents and a group of Radio 4 listeners ask the questions.

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Producer : Dymphna Flynn.