Simon R. Green, . . Roc, $14 (320pp) ISBN 978-0-451-45867-4

The author of the popular Deathstalker series (Deathstalker War, etc.) offers another wildly fantastic extravaganza bound to please his many fans, even if it won't win him new ones. Toby Dexter, a bored 33-year-old clerk at Gandalf's bookshop in Bradford-on-Avon, becomes an unlikely hero when he follows a woman (the mysterious Gayle, at whom Toby has often gaped during his daily commute) into a doorway she creates by pointing at a wall. Suddenly, Toby finds himself in Mysterie, a fantasy world chock-full of gods and devils and coexistent with Veritie, our mundane world. Gayle warns him that she is beyond mortal love, and is instead preoccupied by a power struggle between Good and Evil—with the latter being represented by the Serpent in the Sun, who seeks dominion over everything. Even worse, Gayle says, is that Toby is a "focal point" who will ultimately decide "the fates of people and the world." It's a tall order for a little guy, but Toby's up to it. Magical characters abound and enthusiastically cross the borders between the real and the fantastic: there's the immortal PI Jimmy Thunder, a descendant of Thor; Leo Morn, a bitter and alienated werewolf; the evil Angel, who is restored cleansed; and many more. Green obviously doesn't want to lose favored heroes, so the one loss is Nicholas Hob, son of the Serpent and Luna, Gale's ditsy sister (though Toby himself is shot dead temporarily). Green often pauses to discuss local history, but remembers in time to continue the action and ultimately serves up a happy ending. (Feb. 5)