All of Mark Haddon’s fiction for adults has, until now, been rooted in contemporary realism: emotionally intelligent, yet possessed of a light touch and a sweetly British sense of the absurd. You could argue that his best-known novel, The Curious Incident of the Dog in the Night-Time, is a work of deep imagination; the book, though meticulously realistic, is told from the point of view of a teenager with Savantism. But with his new novel, The Porpoise, Haddon goes deeper still. This time he gives us the gods and goddesses of the ancient world, priestesses and pirates, carnelian and amber. It’s a different kind of storytelling, rich as brocade and powerful indeed.