An undersized high-school boy, Edward Small, Jr., who consoles himself by imagining an allosaurus named Alexander that wreaks vengeance on the people who make Edward uncomfortable, trades in his fantasy when real dinosaur bones are discovered in a local tar pit. Edward is not a typical fictional teen-ager. Though he's at odds with his father, he's unabashedly fond of his mother and plays cards with his little sister. Plagued by a survival instinct that shames him when he dodges fast balls on the baseball diamond, and a dread of public speaking that gets him into scrapes with his math teacher (who is determined that Edward must eventually explain Chapter 33 to the class), Edward is a low-key hero whose many niggling problems seem a little old-fashioned. After he discovers a dinosaur bone at the tar pit, his vengeful daydream has a terrifying run-through as a nightmare in which Alexander destroys Edward's family, which jolts Edward into reform: as negative brooding is replaced by constructive action, he finally gets through the math report with honor, makes friends all around (even with his father), and is the hero of the hour when the rest of the dinosaur bones are dredged up from the tar pit. Though Edward's problems and the ways he tries to work them out are true to life, and the story, with Seidler's ear for cadence and wry humor, reads smoothly, this is a little tame, the ending too pat--disappointing after last year's wonderfully imagined fantasy, A Rat's Tale. And readers may feel cheated when they discover that the marvelously fierce dinosaur that Richard Egielski has painted for the jacket is only a figment of Edward's imagination.