A Worthy lesson--about kindness to ""retards,"" to put it baldly--is unfortunately cloaked here in melodrama. ""The man was like a giant spider,"" the book begins, ""with an enormous round midsection from which erupted arms and legs, all clothed in black . . . Dark hair grew wildly upon his head and sprouted from his ears and nose in short tufts."" This fearsome creature, 17-year-old Cindy soon learns, is ""Just Vernon,"" a young man little older than she who works in the same supermarket as her mother. And, insists her mother: ""He isn't one bit dangerous . . . I won't have you being nasty to him."" We see Vernon clumsily reaching out to Cindy, and Cindy clumsily responding; her mother, made ill-tempered by a diet (?!), taking fright; Vernon, into whose mind the text intermittently switches, misunderstanding Cindy's hesitations--and, meanwhile, some comic by-play involving Cindy's skinny, gluttonous friend Myrna and a basketball star who takes a perverse fancy to her. In the outcome of that, Myrna turns into a swan; into the outcome of the, Cindy-Vernon contretemps, she finds him when he runs away and he, settled into a sheltered workshop, becomes almost presentable. Ostensibly, they've been good for one another--but the reader can't help wondering why Vernon's very bourgeois parents let him go around looking freakish in the first place, or what was supposed to be wrong with Cindy besides her fear of driving a car. As high school juniors, moreover, all the kids are miscast.