Although she's the daughter of sorceress Jaive, Tanaquil herself has no magic; but she does have the ability to mend anything. When the peeve (a furry desert animal that is able to speak as a result of Jaive's chronically unregulated magic) digs up the skeleton of a unicorn, Tanaquil even fixes that, with the aid of wires and gears--only to have her mother's uncontrollable magic bring the construction to life as the terrifying Black Unicorn, which draws Tanaquil to the city. There, she discovers her father, the cold prince Zorander; her sister, princess Lirza; and a broken gate to a perfect world, the unicorn's home. She repairs the gate but cannot stay in the perfect world; instead, she comes home to explore her own, leaving Lirza to tend their father, who is shattered by his brush with the Black Unicorn. This is typical Lee--an aura of mechanical madness and menace, made bittersweet here by the two lonely sisters who find each other only to be parted, and by the indomitable Tanaquil, who has the good sense to prefer her own world, warts and all. The alternately terrified and rambunctious peeve, soiling rugs and biting soldiers at random, creates comic relief. Lee's lively, imaginative style and pungent observations should recommend this to fans of Diana Wynne Jones. Illustrations not seen.