Mike Lewis is an awkward, misanthropic 16-year-old who tunes out his parents and his problems by turning up the volume of his headphones or by zoning out in front of his computer. Outside his bedroom door, his parents are arguing again. Sandy and Ron need some time together to repair their strained marriage. They've conceived a plan to use up Mike's summer vacation and, this time, the terms are non-negotiable. Mike's fate is sealed. He is exiled to the wilds of Colorado to spend six weeks with his grandfather whom he doesn't even know.Mike's grandfather, Ben Maxwell, is a rancher and all-around cowboy. He thinks that getting close to his daughter's boy will somehow make up for the ten years he's lost by bearing a grudge. When Sandy grew up, she left the ranch and broke his heart. It took the passing of Ben's devoted wife to get them speaking again.
Nothing could prepare Ben for the invasion of "planet teen." Mike's dark presence and dismissive manner rub Ben the wrong way. With the help of Ben's close friend, Eli, Ben comes to understand that his grandson's discontent stems from his low self-esteem and the fact that he has never in his life accomplished anything. Mike does, however, succeed in alienating most everyone in town when he unfurls a mean-spirited prank involving an American flag on the Fourth of July. Ben makes the only decision there is to make -- Mike must leave.
Mike is ecstatic about going home until he discovers his means of travel will be by horseback. It is an 800-mile stretch between Ben's Colorado ranch and the California coastline. Ben sets out for the last great ride of his life and Mike unwittingly sets out to become a man. Together they learn what it means to forgive and be forgiven and what it means to be a family.