Justin Zeckendorf, Margaret Zachary, and Jessica Zander are the Zs. Because they're the last three names on the fourth-grade roster, they are always chosen to be a team on class projects. The Good Deed Contest is no exception, and Justin is not looking forward to working with the two know- it-alls, Margaret and Jessica. But when he hears that first prize will be a trip to Tidal Wave Water Park, he becomes more enthusiastic. Justin is the Idea Man, and he thinks of unusual ways to get good-deed points fast, but unfortunately his ideas are generally unsuccessful: He sells photocopies of raffle tickets and nearly causes a riot when 61 people all have the same winning number; he tries to wash his neighbors' window, but doesn't close it first and soaks their living room; he helps a woman across the street, although she had been standing on the side she wanted to be on to begin with. The Zs end up losing points rather than gaining them, and before they know it they're in the hole at -30 points. Justin thinks that if he can find the car thief that's been plaguing the neighborhood his team will win, but first he and his mother work out a way for him to slowly work the Z team back toward positive numbers. Korman's (The Toilet Paper Tigers, 1993, etc.) tale is cringe-inducing in the finest comic manner, and the super pacing of this book will keep readers engaged through the final surprise scenes. (Fiction. 7-9)