An incredibly inventive fantasist inundates the reader with a cascade of magic, so artfully deployed that it never threatens to weigh down her buoyant story. Christopher (who appears as a full-fledged magician in Charmed Life, etc.) is here an apprentice with access to an array of parallel worlds: in one (12B, recognizably ours), technology began its vigorous growth in the 14th century; in Christopher's (12A), a complex system of available magic seems to be as luxuriant and fascinating (or daunting) as technology is in 12B. Exploring other worlds, Christopher is made the dupe of illicit smugglers of dragon's blood and mermaid parts. Meanwhile, back in 12A, he becomes the Chrestomanci's ward and heir and discovers how he has been used by the evil forces--just in time to make some clever, and daring, rescues. Christopher learns much more than magic--including how he appears to others and what those others are behind their masks, magic and otherwise--as well as loyalty and compassion. Never simplistic, Jones rarely creates a wholly good or wholly evil character. Her ebullient wordplay (the crucial eleventh world is both elven and devilish); her humor both slapstick and satirical; and her prestidigitation with ideas should delight her fans (the wicked Dright says, "I put them [the several lives of Chant's guardian] into the form which is easiest to deal with [a boy]" and, as Jones adds, "Like everything he said, this was full of other meaning").