Harlon Eldrick's mother is dying of recurrent breast cancer and wants him to go tell his father. Harlon lives in Cambridge, Massachusetts, and his father lives across the country in a small collection of buildings called Black Dog, Washington. Harlon wants to make this an adventure. He will take the train to Chicago and hitchhike from there to Black Dog. It's been over a week, since Harlon left Chicago on a trip that's been anything but an adventure. He is welcomed into a semi by Steve Lennard for what he hopes is his last ride.