The Pteranodon kids and their dome-headed friend Spikey Stygimoloch meet a brother and sister, Patrick and Pamela Pachycephalosaurus, two dinosaurs with enormous dome heads. Spikey bonds with the Pachycephalosaurus. Patrick and Pamela are athletes who invite our kids, Mom, and Spikey along to watch them use their impressive dome heads to play a volleyball type sport called, Dome Ball. Don has a large collection of things he's found in nature, but he's missing one hard-to-locate item - amber. On the Dinosaur Train, Don and the other Pteranodon kids find out that Gilbert is also looking for amber. At Amber Arroyo caves, Don and Gilbert separately search for and find amber, eventually bonding over their discoveries.