Moscow, 1958. At the height of the Cold War, secretary Lois Vale is on a deep-cover MI6 mission to identify a diplomatic traitor. She can trust only one man: Johann, a German journalist also working covertly for the British secret service. As the trail leads to Vienna and the Black Sea, Lois and Johann begin an affair but as love grows, so does the danger to Lois. A tense Cold War spy story told from the perspective of a bright, young, working-class woman recruited to MI6 at a time when men were in charge of making history and women were expendable.