Very Special Agent Fifi was described as 'one of the most expert liars in the world'. Employed by the Special Operations Executive (SOE), Churchill's wartime spook organisation, her job was to entrap trainee agents and test their mettle in the field. Kept secret for seventy-five years, her existence long treated as a myth, Fifi's files were declassified in 2014 and her identity revealed. She was Marie Chilver, a half-Latvian, half-British escapee...