It's an ordinary afternoon in 1938 for the celebrated American novelist St John Fox, hard at work in the study of his suburban home -- until his long-absent muse wanders in. Mary Foxe (beautiful, British and 100% imaginary) is in a playfully combative mood. ''You're a villain,'' she tells him. 'A serial killer ...can you grasp that?'' Mr Fox has a predilection for murdering his heroines. Mary is determined to change his ways. And so she challenges him to join her in stories of their own devising, and the result is an exploration of love like no other. It isn't long before Mrs Daphne Fox becomes suspicious, and St John is offered a choice: a life with the girl of his dreams, or a life with an all-too-real woman who delights him more than he cares to admit. Can there be a happy ending this time? Mr Fox is a magical book, as witty as it is profound in its truths about how we learn to be with one another.