Ralph the mouse ventures out from behind the piney knothole in the wall of his hotel-room home, scrambles up the telephone wire to the end table, and climbs aboard the toy motorcycle left there by a young guest. His thrill ride does not last long. The ringing telephone startles Ralph, and he and the motorcycle take a terrible fall - right to the bottom of a metal wastebasket. Luckily, Keith, the owner of the motorcycle, returns to find his toy. Keith rescues Ralph and teaches him how to ride the bike. Thus begins a great friendship and many awesome adventures. Once a mouse can ride a motorcyle ... almost anything can happen!

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.

Ralph's pesky cousins are wrecking his motorcycle, and his janitor friend, Matt, is in trouble because there seem to be mice in the hotel. All in all things are not going well at the Mountain View Inn. So Ralph persuades his young pal Ryan to take him to school. Ralph is an instant hit with Ryan's classmates. But he doesn't like being forced to run through a maze or the threat of an exterminator coming to the school. Worst of all, Ryan gets into a fight with a classmate, and Ralph's precious motorcycle is broken. Is Ralph S. Mouse smart enough to steer this sad situation to a happy ending?