When a pack of pesky, migrating trilobites overrun the ship, Big Lizard has to use a hidden talent to lure them away. But one little trilobite, Rex, decides to stay.

Searching for a vital part of the ship that was lost during their crash-landing, Cosima and Big Lizard find Dunk stuck on a beach. They use science to save the day and make a new friend.

Dad drops an essential gizmo in a hard-to-reach place. Big Lizard takes them on an underwater adventure to meet Ammon, the tentacled solution to their problem!