A personal trip turns perilous after the murder of a British spy in Washington, DC, forces Elena Standish to face dark family secrets in this exciting 1930s mystery by best-selling author Anne Perry.

On a family trip to Washington, DC, Elena Standish is delighted to visit her mother's parents for their anniversary and celebrate with influential friends of her grandfather, a prominent scientist. Even Franklin and Eleanor Roosevelt will attend the party. But the event comes to a sudden and tragic end when one of the guests, Lila Worth, is run over by a car in the driveway outside. Elena realizes that Lila had been trying to tell her something, and when a call from Peter Lucas back home at MI6 confirms that Lila was a British spy, Elena pairs with the American secret service to find out what vital information the young woman had in her possession.

To further complicate Elena's trip, her grandfather is arrested for the murder. Desperate to clear his name and save her family from disgrace, she looks more deeply into her grandfather's scientific life and discovers that Lila had been desperately trying to keep the latest developments in nuclear fission out of the Nazis' hands. Her grandfather's business secrets run deep, it appears, and as Elena begins to question his loyalties, she wonders if she can trust anyone in this dark new world order.