In 1926 Agatha Christie vanished, then reappeared eleven days later without explanation. It was a tabloid sensation—a mystery that, nearly a century later, remains unsolved. Fast forward to today: More than a little lost herself, a Christie superfan named Lucy makes the pilgrimage to the author’s estate. When she happens upon an unpublished diary written in Christie’s own hand, Lucy resolves to crack the case once and for all. In parallel storylines that blend past, present, and Poirot, Mrs. Christie proves that sometimes you need to disappear in order to find yourself.