Spring begins in the sub-Antarctic islands with Elephant seals returning from the sea to fight for supremacy over their harems, while five million Macaroni penguins battle through the crashing waves to court and breed. Further south, spectacular time-lapse sequences reveal a continent only just being freed from the ice trap. There is also rare underwater footage of the hardier penguins as they venture south to reach their traditional breeding grounds.

Winter approaches and Antarctic species prepare to migrate north to warmer climates. The Emperor Penguin though, breaks all the rules. Meanwhile, storms ravage the continent and the seas begin to freeze over. Further North, on the sub-Antarctic islands, fur seal pups are beginning to swim and albatross chicks are fledging.

A season of complete darkness, and the worst weather anywhere on the planet - it's midwinter in the Antarctic. The hostile landscape seems completely devoid of life, but under the ice life still abounds. Ghost-like white fish are kept alive by anti-freeze in their blood and giant seaspiders patrol the sea bed. While in the centre of the continent, male Emperor penguins huddle for warmth throughout the winter, each incubating a single egg.

For humans, too, survival in the Antarctic is a severe challenge. The final episode traces the exploration and exploitation of the continent and its surrounding islands. It also examines the difficulties encountered in the making of the series, and looks at the long term issue of human activity on the continent. Should its resources be exploited or should Antarctica be preserved as a National Park?