When Doc, an older longneck that Littlefoot believes to be the legendary Lone Dinosaur, arrives unexpectedly, the kids are convinced he's there to drive Chomper but of the Great Valley. While Littlefoot tries to discover Doc's true intentions, Cera leads the other kids on a wacky journey in an attempt to hide the panic-stricken Chomper.

A big wind blows Petrie and Guido out of the Great Valley and into the Mysterious Beyond. After a rough landing, the two comically bumble their way around Black Rock until they meet Swooper, a blind flier. Each using their individual talents, the comical trio work together to brave the fierce winds and attempt the dangerous journey back home.