149 million years ago, Late Jurassic (Oxfordshire) Filming location: The Bahamas, New Caledonia

The episode begins with a Eustreptospondylus being snatched from the shore by the pliosaurLiopleurodon. Meanwhile, the ichthyosaur Ophthalmosaurus live-breeding ceremony is the main event taking place, as hundreds of Ophthalmosaurus arrive from the open ocean to give birth. In the midst of the birthing sharks and other predators, including Liopleurodon, are on the hunt, and when one mother has trouble giving birth, a pair of Hybodus sharks go after her, but are frightened off by a male Liopleurodon, which eats the front half of the Ophthalmosaurus, leaving the tail to sink down and be feasted upon by the Hybodus. Meanwhile aEustreptospondylus swims to an island and discovers a turtle carcass that it must contend for with another Eustreptospondylus. Later during the night, a group of horseshoe crabs gather at the shore to lay their eggs, which attracts a flock of Rhamphorhynchus in the morning to eat the eggs. However a few of the pterosaurs are caught and eaten by a Eustreptospondylus. While the Ophthalmosaurus juveniles are growing up, they are still hunted by Hybodus, which in turn, are prey for the Liopleurodon. At one point, while the male Liopleurodon is hunting for prey, he is encountered by a female Liopleurodon. After the male bites one of her flippers, she retires from his territory, followed by a group of Hybodus catching her trail of blood. A typhoon then strikes the islands, and kills many animals, including severalRhamphorhynchus. The Liopleurodon himself is washed ashore and lays upon the beach, eventually suffocating under his own weight. The carcass then becomes the banquet of a group of hovering Eustreptospondylus. At the end of the episode, the juvenileOphthalmosaurus that survived the storm are now large enough to swim off to live and breed in the open sea.

Animals Ophthalmosaurus · Liopleurodon · Eustreptospondylus · Cryptoclidus · Rhamphorhynchus · Hybodus (identified as shark) ·Perisphinctes (identified as ammonite) · Leptolepis · Horseshoe crab · Squid · Turtle (carcass) · Jellyfish · Fish · Coral

106 million years ago, Middle Cretaceous (Antarctica/Australia)
Filming location: New Zealand

A few hundred kilometres from the South Pole, a clan of herbivorous Leaellynasaura are seen emerging to activity after months of total darkness. Now with the coming of spring, the members of the clan are shown feeding on the fresh plant growth and building nests so they can lay their eggs. A male amphibian Koolasuchus has also woken up from hibernation and heads to a river where he will stay during the summer. Out on the rocky river banks, migrating herds of herbivorous Muttaburrasaurus have arrived to feed on the fresh vegetation and lay their eggs, also dealing with blood-sucking insects. By summer, many of the Leaellynasaura clan's eggs have been eaten, but those of the matriarch hatch successfully. A male polar allosaur is shown hunting the Leaellynasaura and Muttaburrasaurus. The Leaellynasaura clan continues to prepare for the winter, as well as raising the young that have now grown. When autumn arrives, the Muttaburrasaurus herd begins to head back north, and the Koolasuchus leaves the river to find a pool in the forest to hibernate through the winter. However, during the migration some Muttaburrasaurus become lost in the forest and the noise they make in the process of trying to get back to the herd prevents the Leaellynasaura clan's sentry from hearing the polar allosaur approaching. In the confusion, the allosaur manages to catch and kill the matriarch of the Leaellynasaura clan, while only one of the hatchlings survives the year. After the last day passes in a matter of minutes, winter descends and the forest becomes almost completely darkened, requiring image enhancement to the camera to view what wildlife are still active. The Leaellynasaura clan is able to stay active despite their social order being in disarray, using their large eyes to help them forage for food. During this time, the clan and other fauna use various methods of dealing with the cold, including suspended animation, hibernation or using group body temperature to maintain heat. Finally, spring returns, and two Leaellynasaura males challenge one another for the right to mate, and after a short confrontation, the clan establishes a dominant pair once again.

In the end it is accepted that the shifting of the continents will soon pull the landmass closer to the South Pole, and that the forests, and all these unique dinosaurs will soon disappear.

Animals Leaellynasaura · Koolasuchus · Polar allosaur (likely Australovenator) · Muttaburrasaurus · Steropodon (identified as Mammal) · Giant Weta · Tuatara · unidentified pterosaurs · blood-sucking insects