When the boys return to Dino World this time, everything is different. The trees, the landscape, it's almost like they've gone to another place. But that's not it-it's another time! Tom and Jamie have been transported to the Jurassic period, which means they'll have all new dinosaurs to meet. But their exploration is cut short when a sudden downpour separates a stegosaurus egg from its mother-and plops it right into the boys' laps. And when the "steg egg" starts to hatch, Jamie and Tom know they're on the clock to get the baby dino back to its mother. If only they could find her!