Edinburgh, Scotland. It's been one thing after another for Detective Grace McKenna and her team at the fledgling Portobello Detective Agency, and she's finally enjoying some peace as the leaves turn and autumn beckons. But when a wealthy local landowner contacts her about a case so sensitive he can't even discuss it over the phone, Grace is instantly intrigued. Russian collector Sacha Komorov lives out of the public eye, despite his immense wealth and marriage to a famous ex-prima ballerina. As Grace gazes at the ominous silhouette of his Scottish estate, Castle Traprain, with its high walls and thrusting turrets, a shiver runs down her spine. Komorov himself is just as forbidding as he discloses the disappearance of a priceless rose-diamond Fabergé egg from his collection. It's an inside job, and he needs Grace to uncover the traitor within his own household. As Grace dives into the case, her team goes undercover at Castle Traprain to win the trust of the staff. But things take an unexpected turn when Komorov's beautiful and troubled wife, Katya, begs for Grace's help to catch a disturbing stalker. Are the two cases connected? And why does Katya want to keep her husband in the dark about hiring Grace? The plot thickens when one of the potential suspects is found murdered in the Housekeeper's quarters. It seems this is no ordinary jewel thief. The killer lurking within Castle Traprain will do anything to achieve their ends and, as the tension mounts, Grace and her team find themselves ultimately becoming targets in an increasingly deadly game...