THE THREE LIVES OF HARRIS HARPER

Harris, 12, has a summer job baby-sitting preschooler Jamey Benya, who is a handful. Harris is impressed with Jamey's wealthy parents, who contrast sharply with his own messy, easygoing, financially just-about-making-it mother and father. When he's not sitting, Harris hangs out with his big-talking best friend, Bert, whose sole aim in life is to call ``babes'' on the phone and make dates for him and Harris. Harris tells his parents that he won't be going on a family camping trip and secretly nurses a hope that the Benyas will adopt him. Then Jamey runs away; in his search for the child, Harris learns something about both the Benya family and his own, all too predictable to matter much. Bert's machismo is far more offensive than amusing, but Harris is a reassuringly normal hero, whose actions are mostly believable. He's stuck in a well- worn plot, though, where Cullen (The Backyard Ghost, 1993, etc.) surrounds him with little more than cardboard characters; readers will smell the set-up before he does. (Fiction. 10-13)