The Christie Affair

De Gramont (The Last September) offers an intriguing new theory of why Agatha Christie disappeared for 11 days in this superior thriller, which places the woman Christie’s husband, Archie, was having an affair with at the time—here the fictional Nan O’Dea—at its center. A gripping opening sentence teases O’Dea’s dark side (“A long time ago, in another country, I nearly killed a woman”). In December 1926, Archie decides to reveal the affair to his wife, to whom the news comes as no surprise. Agatha, however, is taken aback by her husband’s declaration that he is both leaving her and seeking a divorce. A day later, the world-famous mystery author vanishes, and her abandoned car is found near a body of water notorious for corpses being found in it, leading some to suspect the writer killed herself. Flashbacks flesh out the backstory of O’Dea, who at 19 was sent to a convent by the head of the family she was working for in Ireland after getting pregnant by his son. De Gramont treats O’Dea’s story with sympathy and care, highlighting the bleak circumstances for both women in the historical period and teasing out the motivations for breaking up the Christies’ marriage. This is an enjoyable reimagining of a scandal whose exact nature remains a puzzle a century later. (Feb.)