Mike Evans goes through the time portal to find his friend Shannon and her troublesome brother Jeff, but he soon finds they all have bigger problems--a robot who wants to repopulate the Earth with dinosaurs and a group of Tyrannosaurus rex babies who remember Mike from New York.

His father and everybody else at the museum in New York is excited over the dinosaur eggs that Mike Evans found in Montana--the trouble is they are hatching and Mike will need the help of his mysterious and time-traveling friend Shannon to capture them before they wreck the museum.