Gregory Maguire's fourth novel, Mirror, Mirror, opens with a series of compelling but opaque blank-verse lines: "I am a rock whose hands have appetites / I am a hunter who cannot kill / I am a monster who let the child go," and so forth. Over the course of his story, the meaning of each line in turn becomes clear, as Maguire fleshes out the skeleton forms of his compelling but vague poetic concepts. He's followed a similar pattern with most of his novels: Three of his four books revise and contextualize familiar fables, putting meat on the original stories' bones. His debut, Wicked: The Life And Times Of The Wicked Witch Of The West, presented The Wizard Of Oz's cackling green harridan as a misunderstood political activist with a rich backstory, while his follow-up, Confessions Of An Ugly Stepsister, set Cinderella in 17th-century Holland, among tulip speculators and Dutch artists. Mirror, Mirror continues the theme by placing Snow White And The Seven Dwarves in 16th-century Italy, where an expatriate landholder beholden to the infamous Borgia family is dispatched on what seems to be a fool's errand, leaving his motherless child behind to become the ward of Cesare and Lucrezia Borgia. The Borgias' real-life history of political opportunism, murder, and incest comes into play, and it meshes surprisingly well with the Snow White fairy tale. It's not at all difficult to imagine the real Lucrezia Borgia sending a child into the forest with a hunter ordered to kill her and bring her heart back in a box. But while Maguire has picked his time and place cleverly, and shows similar deftness in illustrating his setting and his characters, he never scratches his premise's colorful surface. Too many of the well-drawn principals turn out to be window dressing, too many of the plotlines dribble out into emptiness, and too many of his elaborations amount to misdirection. In places, Maguire brings Snow White's more fantastical elements down to earth: His magic mirror doesn't talk, for example, but instead just reflects impartially. But other story elements make the original tale's conceits look tame, particularly when Maguire introduces his baroque version of the seven dwarves, then involves the Biblical Tree of Knowledge in the plot. Maguire's tales are invariably dense and involved, more complicated and in a way more rewarding than their source material. But Mirror, Mirror is the first book he's written that seems more farfetched than its basis in myth. It's a beautifully stylized story, and enjoyable to read. But too much of it is smoke and (no pun intended) mirrors.