Since the death of his grandfather, Leo's number one chore has been to chase after his grandmother who seems to wander away from home every few days. Now, Gram's decided to roam farther than ever. And despite his misgivings, Leo's going along for the ride. With his seventeen-year-old cousin, Abbey, and an old, gassy dog named Kermit, Leo joins Gram in a big, old Buick to leave their Pennsylvania home for a cross-country road trip filled with foldout maps, family secrets, new friends, and dinosaur bones.