The delightful duo that brought readers Appaloosa Zebra (2002) and Runaway Radish (2001) returns with the story of Scamper, a white pony, and two sisters who take him to a local horse show. Throughout the day, as they go in halter class, lead line, pleasure, equitation, and trail classes, they pin their hopes for winning on the costume class, when Scamper himself becomes an American flag. A sudden rainstorm dissolves their hopes—but a kind judge sees Scamper’s true colors in the end. Haas is simply terrific at horse stories for readers too young to love the Thoroughbreds series, and Apple’s horses—the gentle, skinny pink roan, the cranky palomino, and best of all Scamper—are so real you expect them to trot off the page. A brief afterword explains horse show classes, and a note in the bio says that the story is based on a costume Haas’s own Scamper wore in a Bicentennial show. Winning. (Picture book. 4-9)