The Pteranodon family takes the Dinosaur Train to Adventure Island, a new theme park on a volcanic island! The Conductor's archrival Thurston is in charge: he proudly shows off the park's amazing robot dinosaurs! When an earthquake causes the pressure to get too high, the malfunctioning robots go rogue. It's up to Buddy and his siblings to navigate across the island and reunite with their parents.

Barbie stars as Merliah, a surfer who learns a shocking secret: she's a mermaid! She and her dolphin friend set out for an undersea adventure to rescue her mother, the queen of Oceana.