The series begins in the 'land of the sabre-tooth'; North America, a continent that was half covered by ice that was up to two miles thick. Yet this frozen land also boasted the most impressive cast of Ice Age giants in the world. Across locations such as the Grand Canyon, the sands of Arizona and the coast of California, Alice traces the movements of Ice Age beasts like bear-sized sloths, vast mammoths and the strange beast known as the glyptodon. These leviathans all have one thing in common: they were stalked by the meanest big cat that ever prowled the Earth, armed with seven-inch teeth and hunting in packs - Smilodon fatalis, the sabre-toothed cat.

In the Land of the Cave Bear, Alice ventures to the parts of the northern hemisphere, hit hardest by the cold - Europe and Siberia. High in the mountains of Transylvania, a cave sealed for thousands of years reveals grisly evidence for a fight to the death between two staving giants, a cave bear and a cave lion. Yet Alice discovers that for woolly rhinos and woolly mammoths, the Ice Age created a bounty. The Mammoth Steppe, a vast tract of land which went half way round the world, provided food all year round, for those that liked the cold. It was these mammoths that Europe's most dangerous predators hunted for their survival.

Even after thousands of years of ice crushing the northern hemisphere and temperatures of 20 degrees lower than those of today, many of the great giants of the ice age still walked the earth. It was only when the world had warmed up again that mammoths, woolly rhinos, sabre-toothed cats, giant ground sloths and glyptodonts finally became extinct. Professor Alice Roberts sets off on her last voyage back to the Ice Age to discover why.