Grant McAllister, an author of crime fiction and professor of mathematics, once sat down and worked them all out. But that was thirty years ago. Now he's living a life of seclusion on a quiet Mediterranean island - until Julia Hart, a sharp, ambitious editor, knocks on his door. His early work is being republished and together the two of them must revisit those old stories. But as she reads the stories, Julia is unsettled to realize that there are parts that don't make sense. Intricate clues that seem to reference a real murder. One that's remained unsolved for thirty years.