Finding herself and her younger sister and brother in a hazy past, alternately pursued and pampered, able to communicate only by signs. Dolly is reminded of watching a ""grotty foreign film"" at school, and the analogy holds for the reader. He knows that red-headed Sara is standing in for red-headed Magra, mislabeled a witch, enabling Magra to reach the Northern king and help him drive the sea-raiders from England, but the role of Celts and Angles and Saxons is obscure, and even the latterday situation--three young people pony-trekking to Grandmother's--takes some time to grasp. (Whereas the ages of the three are entirely elusive: Dolly is five years older than Sara, eleven years older than Andrew.) The magic is the work of a stone that makes past and future palpable, hardly a novel device, but Magra's possession of it leads to the strongest episode in the book: isolated by her presumed power, exalted but not loved, she welcomes the call to the north and the chance to be a queen, a priestess, a sacrifice--not least a sacrifice to unite the native tribes (no more fearsome, in her view, than going to battle). And when she has made the change with Sara, and changed back, she loses the stone without regret ""because a sacrifice must be clean of things, especially of magic."" We don't see Magra to her destination; the bulk of the book is about Dolly and Sara and Andrew, who are only fitfully interesting in their befuddlement, and unwitting pawns to the end. Dense and, after leaving Magra, not worth penetrating.