One of the most popular characters ever created by Beverly Cleary is the small brown mouse named Ralph, whose modest appearance disguises the soul of a daredevil. Now he returns in a book that tells how he runs away from home on his mouse-sized motorcycle in search of freedom and adventure. Ralph's destination is a summer camp, where he hopes crumbs from peanut-butter-and-jelly sandwiches will be plentiful. But instead of finding freedom, he lands in a cage, doing endless loop the loops on an exercise wheel. The story of how Ralph and a lonely boy named Garf discover they speak the same language involves a villainous cat, a grouchy hamster, and many campers. Each episode is funnier than the last. On one level, Mrs. Cleary's story is a delightful tour de force. On another, it delivers a message about running away that is all the more effective because it is unobtrusive.