After a car accident strands them at opposite ends of the Blue Ridge Parkway, eleven-year-old Abby and her beloved sheltie Tam overcome months filled with physical and emotional challenges to find their way back to each other.

Marty goes in search of the mythical Train of Lost Things, hoping that by finding his most precious possession he can save his father from cancer, but he discovers that, without a driver and conductor, the train is malfunctioning and only Marty and his new friends can fix it.