In 1948, the shadow of war still lingers over Britain. Beattie Cavendish, formerly of the Secret Operations Executive, refuses to settle into a conventional life. When offered an undercover role at the newly formed GCHQ, she eagerly accepts. Tasked with monitoring the Bowen family, her mission takes a deadly turn when their housekeeper, Sofia, is murdered. Teaming up with war-weary detective Patrick Corrigan, Beattie uncovers a dangerous web of spies and secrets centred around The White Pearl Club, an establishment in Soho that caters to gentlemen with exotic tastes. As powerful forces try to bury the truth, she must rely on her skills to survive a ruthless game of deception and the dawn of the Cold War.