In December 1926, Agatha Christie goes missing. Investigators find her empty car on the edge of a deep, gloomy pond, the only clues some tire tracks nearby and a fur coat left in the car—strange for a frigid night. Her World War I veteran husband and her daughter have no knowledge of her whereabouts, and England unleashes an unprecedented manhunt to find the up-and-coming mystery author. Eleven days later, she reappears, just as mysteriously as she disappeared, claiming amnesia and providing no explanations for her time away.

The puzzle of those missing eleven days has persisted. With her trademark historical fiction exploration into the shadows of the past, acclaimed author Marie Benedict brings us into the world of Agatha Christie, imagining why such a brilliant woman would find herself at the center of such murky historical mysteries.

What is real, and what is mystery? What role did her unfaithful husband play, and what was he not telling investigators?

Agatha Christie novels have withstood the test of time, due in no small part to Christie's masterful storytelling and clever mind that may never be matched, but Agatha Christie's untold history offers perhaps her greatest mystery of all.