One peaceful evening in the Valley - Chomper is running around playing and snapping at small insects. He is unaware that slowly his hunt for the insects leads him astray and out of the Valley........

The scene changes and Little Foot, Cera, Ducky and Spike wonder where Chomper has gone. Suddenly Petrie comes flying in to tell them she saw Chomper leaving the Valley.

Quickly they all decide to set off to their friend's rescue, even though it means they must venture outside of the Valley and into the Mysterious land beyond.....