Exhausted, it no longer has the energy to pull itself to safety. And the killers are moving in. Game over. Although such team hunts are rarely seen, scientists believe they may be the most complex ever documented in the natural world. They were first witnessed by Captain Scott and his men when they came to explore Antarctic one hundred years ago.

Journeying further south, the fragmenting ice is replaced by a permanent sheet that doesn't know even the heat of summer. It is a barrier that many creatures find impossible. It repels even powerful mink whales. They have to turn back if they can't no longer reach the air that they need to breathe.

Under the ice, life has to be extremely specialized to survive.Few of us will ever experience this strange,mysterious world. And as yet, no one knows much about it. The crystalized surface of ice-style tights provides a home for ice fish whose bodies are full of antifreeze. The sailing of ice shelters those living below it from the violent polar weather that rages above. Little here has changed for millions of years. The cold allows animals to grow very slowly and become giants.