A complex web of thoughts was weaving itself in the bear king's mind, with more strands in it than hunger and satisfaction. There was the memory of the little girl Lyra, whom he had named Silvertongue, and whom he had last seen crossing the fragile snow bridge across a crevasse in his own island of Svalbard. Then there was the agitation among the witches, the rumors of pacts and alliances and war; and then there was the surpassingly strange fact of this new world itself, and the witch's insistence that there were many more such worlds, and that the fate of them all hung somehow on the fate of the child.

In the final installment of his trilogy, Philip Pullman has set himself the highest hurdles. He must match its predecessors in terms of sheer action and originality and resolve the enigmas he already created. The good news is that there is no critical bad news--not that The Amber Spyglass doesn't contain standoffs and close calls galore. (Who would have it otherwise?) But Pullman brings his audacious revision of Paradise Lost to a conclusion that is both serene and devastating. In prose that is transparent yet lyrical and 3-D, the author weaves in and out of his principals' thoughts. He also offers up several additional worlds. In one, Dr. Mary Malone is welcomed into an apparently simple society. The environment of the mulefa (again, we'll reveal nothing more) makes them rich in consciousness while their lives possess a slow and stately rhythm. These strange creatures can, however, be very fast on their feet (or on other things entirely) when necessary. Alas, they are on the verge of dying as Dust streams out of their idyllic landscape. Will the Oxford dark-matter researcher see her way to saving them, or does this require our young heroes? And while Mary is puzzling out a cure, Will and Lyra undertake a pilgrimage to a realm devoid of all light and hope, after having been forced into the cruelest of sacrifices--or betrayals.