Theo Zephyr

Brad recognizes new boy Theo Zephyr as an incarnation of his own imaginationthe cocky, brave kid who can tame lions and slam-dunk basketballs, and who always gets the better of Gil Brimhall, Brad's nemesis. While Theo plays out Brad's daydreams, Brad realizes that he must get rid of Theo before he prepares for the ""big one,'' the wildest daydream of all. While the appearance of Theo is an intriguing concept, the story doesn't hold up as well as it might. The conversations between Brad and Theowhile thought provokingoccasionally become confusing and bog down the story. But the double-talk can be very funny, too: Theo says, ``You think; therefore I am.'' Readers who enjoy the challenge of the book's philosophical concerns will come away rewarded. Ages 9-13. (September)