Leigh Botts has been author Boyd Henshaw's number one fan ever since he was in second grade. Now in sixth grade, Leigh lives with his mother and is the new kid at school. He's lonely, troubled by the absence of his father, a cross-country trucker, and angry because a mysterious thief steals from his lunchbag. Then Leigh's teacher assigns a letter-writing project. Naturally Leigh chooses to write to Mr. Henshaw, whose surprising answer changes Leigh's life.

Fed up with his timid mother and uncle and his squirmy little cousins, Ralph hops onto his toy motorcycle and zooms down the road to summer camp. It turns out camp is not all peanut butter and jelly sandwiches and fun. A strict watchdog, a mouse-hungry cat, and a troubled boy named Garf lead Ralph on some fur-raising escapades. Perhaps home isn't such a bad place to be, if only Ralph can find a way to get there again.