All murder mysteries follow a simple set of rules. Grant McAllister, an eccentric but brilliant professor of mathematics, once sat down and worked them all out and wrote a set of seven stories to demonstrate. Soon after, Grant disappeared to live on an isolated Mediterranean island. No-one knows why he left. He never came home. Thirty years later, Julia Hart, a smart, ambitious young editor, knocks on his door. Grant's work is being republished, and together the two of them must revisit those old stories. But as she reads the sharp, twisting tales, Julia is unsettled to realise that there are things that don't make sense -- deliberate inconsistencies which Grant is unable -- or unwilling -- to explain. Might they be a trail of clues? And if so, do they lead towards the topic on which Grant is most evasive -- the truth about what happened thirty years before? If Julia wants answers, she must triumph in a battle of wits with a dangerously clever adversary. But she must tread carefully -- she knows there's a mystery, but she doesn't yet realise there's already been a murder ...