Fed up with his bratty family, Ralph the mouse hops onto his toy motorcycle and speeds down the road away from the Mountain View Inn toward Happy Acres Camp, where he encounters Sam, a nosy watchdog, and is captured by a boy named Garfield (or Garf) and kept as a pet. Separated from his motorcycle, Ralph must endure life in a cage with an annoying hamster named Chum. Over time, Ralph and Garf form a relationship similar to the one Ralph and Keith had in the original book in the series.
Ralph's adventures at Happy Acres Camp include escapades with an evil cat, the return of a missing watch, the escape from his cage, and being reunited with his beloved motorcycle. He eventually begins feeling homesick and strikes a bargain with Garf: return the motorcycle and bring him back to the Mountain View Inn, in exchange for clearing Garf's name (the rest of the children at Happy Acres Camp believe Garf was the one who took the missing watch). Eventually, the watch is returned, and Garf reassures Ralph that he will go back home the next day.