Simple-minded, derivative sequel to the best-selling Magic Kingdom for Sale--Sold! (1986). Ben Holiday, ex-lawyer from Earth and now king of the magic kingdom Landover, has a troubling dream: that his former partner in law is in trouble and needs his help. Simultaneously, incompetent court-wizard Questor Thews dreams of recovering the two lost Books of Magic; and the lovely Willow dreams of taming the mysterious black unicorn with a golden bridle. Ben visits Earth, realizes he's been tricked, and rushes back--but the evil wizard Meeks changes Ben's appearance and apparently steals Ben's medallion, source of his magic authority. (Ben is fooled, but readers won't be.) Questor Thews recovers the books of magic, yet one has a hole burned in it, the other contains only drawings of unicorns. Ominously, Willow fails to return. So Ben, outcast and unrecognizable, must try to unravel Meeks' plot against him, accompanied only by a magical, chatty prism cat who offers reams of good advice. The resolution, involving a multiplicity of unicorns, owes a great deal to Peter Beagle. Sprightly if irritatingly obvious fable-weaving, then, and, despite the absence of any profound thinking or involvement, Brooks' enormous popularity should carry this one smartly along.