Introduction

Nigel West was fascinated by the dangerous work of double agents. Spies who pretended to work for one side were really serving the other. Double agents were essential to the allied war effort, notably in an elaborate ruse designed to ensure the success of D-Day. Since the end of the war, the code name Garbo had become legendary in intelligent circles. One former spy called him the most successful double agent of the Second World War. The man who was instrumental in diverting German army strength away from the D-Day landings. Helena Bonham Carter: History's Secret Heroes is on BBC Radio 4 tonight at 9pm.