In 1926, when her husband’s affair became public, Agatha Christie vanished for eleven days. This reimagining is told through the eyes of her husband’s mistress, Nan O’Dea (a fictionalized version of his real-life paramour, Nancy Neele). Agatha and Nan transform from competitors to unlikely allies while the world around them remains cloaked in the dark, unable to grasp the complexities of each woman’s relationship to her past and her female identity.