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 husband and 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 exploration into the shadows of history, 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 a murky story.

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

A master storyteller whose clever mind may never be matched, Agatha Christie's untold history offers perhaps her greatest mystery of all.