Diana Wynne Jones has a remarkable ability to grasp the basic elements of myth or fairytale, twist them sharply, then fit them without undue strain into patterns of her own making. In Power of Three, her most ambitious book yet, she has marched onto that dangerous, old, but not very straight Celtic track along which so many others have strayed recently. Still, if she has not quite avoided all the pitfalls her version is highly distinctive, funny, exciting and with one marvellous twist. It is about the peoples who mythologically and historically have displaced each other within the British Isles. Her heroes—and so for this book, the norm—are three children of the Mound People (the little folk to us) who help to bring their own people together with their traditional enemies…. The surprise comes when we realize that what appears to have been an imaginary country...