The second episode looks at the challenges of hunting in the Arctic, the most seasonal place on Earth. To a predator, seasonal change is a problem. It means that all the parameters of the hunt - the conditions, the strategies, the prey - change too. The only option for the Arctic's top predators, the wolf, the Arctic fox and the polar bear, is to continually adapt to their changing world, exploiting the good times and enduring the bad.

The final episode of the series visits the frontline of the conflict with the world's top predators, meeting the scientists fighting to save them. Crossing five continents and combining landmark natural history footage with real-life human drama, it checks the pulse of the earth's iconic animals, including lions, tigers, polar bears and blue whales. With three-quarters of the planet's carnivores now in decline, can people find ways to live with predators before they disappear forever?

In the fourth episode of the series, legendary nature and cultural photographer Art Wolfe captures the great brown bear with the stunning backdrop of Alaska’s mountains and glaciers, immigrating wildebeests in the plains East Africa, and the hard-to-find gorillas of Uganda.

The story begins with Tyson sitting at a campfire, and telling how the wolf changed through artificial selection, and selective breeding into the dog breeds around today. He then enters the Ship of Imagination, and explains natural selection with the process that helped to create the polar bears. Along the way he talks about DNA, genes and mutation. Next he goes to a forest and describes the Tree of life, this leads him to discussing the evolution of the eye. He then discusses extinction, by going to a monument called the Halls of Extinction, dedicated to the broken branches of the tree of life. Explaining the five great Extinction events. He then tells how some life has survived, and then focuses on the tardigrade. From there he talks about what other kinds of life might have been created on other worlds. He then goes to Saturn's moon Titan. From there he speculates about life and how it first began. He then returns to Earth and tells about abiogenesis and how life changed and evolved. The show ends with an animated sequence from the original series of life's evolution from one cell to humans.

Enjoy this wonderful documentary from Disney Nature about a family of brown bears living in the coastal mountain ranges of Alaska." A brown bear mother named Sky gives birth to two cubs named Amber and Scout in her den on a mountain slope. When April comes the bears will be ready to leave the den. As the bears leave the oncoming summer brings with it a threat of avalanches. Fortunately the bears are able to avoid disaster. Upon reaching the lush valley below, the cubs meet the other bears, some of which pose a threat to the cubs; among these bears are Magnus, a big healthy male, and Chinook, an older male. The family works together to survive the spring, with Sky keeping the cubs safe from Tikaani, a pesky grey wolf...

The film centers on our ongoing mission to explore and come to terms with the Arctic, and the compelling stories of our many forays into this captivating place will be interwoven to create a unifying message about the state of the Arctic today. Underlying all these tales is the crucial role that ice plays in the northern environment and the changes that are quickly overtaking the people and animals who have adapted to this land of ice and snow.