70 million years ago the tropical jungles of the North Pole thundered with the footfalls of hundreds of dinosaurs. This epic sight heralded the start of an annual ordeal, as dinosaurs came together in huge numbers to escape the perils of a dramatic seasonal change. This incredible story is seen through the eyes of one of the most vulnerable members of the herd, a young edmontosaurus, undertaking his first 1000-mile migration south. He has to survive the treacherous and punishing volcanic landscapes, blizzards, landslides, droughts and the deadly predators who lie in wait along the route.