While playing ‘Cold and Hot,’ a game they made up, the Pteranodon kids learn from Mr. Pteranodon that there might be more variety in the desert then they imagined. Their curiosity piqued, they plead for a trip to investigate the desert scene. Mr. Conductor tells them just how diverse plant and animal life can be in the desert. He happens to know a desert mammal Fruitafossor. Upon disembarking from the Dinosaur Train, the Pteranodon kids meet Frankie Fruitafossor, a chipmunk-sized mammal. They quickly learn that their assumption that desert life was hot all the time and relatively uninhabited was incorrect. Come dusk, they find the desert hopping and crawling with life, as creatures emerge all over – mostly underground – where they hide from the blazing sun. Frankie gives our family a tour, including a peek at underground burrows he dug. Back on the desert floor, Don and the siblings can’t believe how cold the desert has become. Nighttime in the desert is a different world than daytime! The family goes back to the Dinosaur Train to warm back up and have a snack.