A millionaire (Stuart Wilson) and his two teenage sons (Tyron Leitso, Wentworth Miller) crash-land on a lost continent where dinosaurs and humans live in harmony.

Karl begins training at the hatchery, where his saurian partner, 26, is born, while sick David gets medical care; as the Sunstones continue to fail and dinosaurs rampage the continent, Zippo urges the senators to send an expedition to the World Beneath.

Karl, David, Marion and Zippo join with the rogue Cyrus Crabb to brave the World Beneath and find a solution for the failing Sunstones.