What does 12-year-old Sarah McDermott do when her mean uncle Frank threatens to commit her beloved grandpa to the County Nursing Home? She decides to "kidnap" Grandpa, with the help of her friend Joey, and take him to Chicago to find a doctor who will declare him competent. Granted, Grandpa has been doing some strange things since his stroke, but Sarah is convinced he is getting better.
The plan is set into motion, and what follows is a wildly hazardous and hilarious 180-mile odyssey from the family farm to Chicago over back roads in an ancient Model-A truck with Joey at the wheel. Joey's observation that Sarah is "always making things sound so simple, and they hardly never end up that way" turns out to be true.