The Conductor, determined to find his missing father, takes the experimental Drill Train and drills a new Time Tunnel that goes as far into the end of the Mesozoic Era as possible, to drill farther into the future and find his father, Trevor Troodon. Once Dad and Buddy and Tiny get wind of this plan, they come aboard, too. So they all take the Drill Train and drill into the future. They come out in the Ice Age of the Cenozoic Era, where they meet a huge, furry Mastodon named Maurice. Maurice helps them search through the icy wastes until they find a feather-covered Northern Troodon who turns out to indeed be Trevor, the father of Mr. Conductor! A happy reunion for all, and they bring him home to the Age of Dinosaurs.