The international bestselling author of The Spy and the Traitor reveals one of the last great untold spy stories of the twentieth century: the woman hidden in plain sight who set the stage for the Cold War.In 1942, in a quiet village in the leafy Cotswolds, an unassuming woman lived in a small cottage with her children and machinist husband, Len. Ursula Burton was friendly but reserved, and spoke English with a slight foreign accent. By all accounts, she seemed to be living a