World War II London: When Victoire "Paddy" Bennett first walks into the Admiralty's Room 39, home to the Intelligence Division, all the bright and lively young woman expects is a secretarial position to the charismatic Commander Ian Fleming. But soon her job is so much more, and when Fleming proposes a daring plot to deceive the Germans about Allied invasion plans he requests the newlywed Paddy's help. She jumps at the chance to work as an agent in the field, even after the operation begins to affect her marriage. But could doing her duty for King and country come at too great a cost? Socialite Friedl Sṯttinger is a beautiful Austrian double agent determined to survive in wartime England, which means working for MI-5, investigating fifth column activity among the British elite at parties and nightclubs. But Friedl has a secret--some years before, she agreed to work for German Intelligence and spy on the British. When her handler at MI-5 proposes that she work with Serbian agent, Dusko Popov, Friedl falls hopelessly in love with the dashing spy. And when her intelligence work becomes fraught with danger, she must choose whether to remain loyal to the British and risk torture and execution by the Nazis, or betray thousands of men to their deaths. Soon, the lives of these two extraordinarily brave women will collide, as each travels down a road of deception and danger leading to one of the greatest battles of World War II.