Every year grizzly bear families in North America depend for their survival on a spectacular natural event: the return of hundreds of millions of salmon from the Pacific Ocean to the mountain streams where they were born. The salmon travel thousands of miles to spawn and then die. The great run not only provides food for bears, but for killer whales, wolves, bald eagles, and even the forest itself. The question is: will the salmon return in time to keep hungry bears alive?
A mother grizzly and her cubs emerge from their den high in snowy Alaskan mountains. Filming from the air the team capture a TV first, following the bears as they negotiate a near vertical slope on their journey to the coast where they await the return of the salmon. Meanwhile, the salmon are making their way to the to river mouths where they must swim upstream and against the current. The programme reveals how they tackle the torrents and leap over waterfalls, a feat equivalent to a human jumping over a house. Dozens of hungry bears eagerly await the salmon that make it up river. In another TV first, underwater cameras record the ingenuity and fancy footwork they use to collect dead salmon from the bottom of deep pools.

The polar regions of our planet may seem beyond the reach of most of us, but they are not beyond our influence. We, unintentionally, are changing these frozen worlds, and these changes will not just affect the poles but the whole planet. On the unforgiving frontier of climate change, polar bears, walruses, seals and penguins find their icy Edens in peril.

Each night, across the planet, our cities illuminate the darkness. Their lights burning brighter than ever before. And whilst we're asleep, animals are making the most of this new neon landscape. The sunset in Los Angeles, Chicago, and Toronto creates worlds of opportunities for the cleverest animals willing to take the risk.

The great mountain ranges are some of the planet's most spectacular landscapes, but they are unforgiving places to live in, and only a few animals have what it takes to live at extreme altitude. Mountain animals are amongst the most elusive in the world, and this film provides unique and intimate glimpses into their secretive lives. Witness the moment four snow leopards come together when a mother and cub become trapped between two rival males. Join grizzly bears as they dance against trees to rub off their winter fur and soar with golden eagles hunting amongst Europe's snow-capped peaks.

There had been other pirate settlements in different places but none of them had worked quite the same way that Nassau did. There was a fort there. People stayed, they built a community on the land. Larger and larger numbers of pirate-minded people were showing up there and starting to develop an economy around themselves. Men like Edward Thatch, later known as Blackbeard, his sidekick, Black Caesar, a former slave, and the pied pirate that led them all there, Captain Benjamin Hornigold.
In the second episode, tensions rise between Benjamin Hornigold and Henry Jennings; their rivalry takes a new direction when Hornigold declares Nassau a pirate republic.

The Pirate Republic of Nassau gets fat attacking trade between Britain and the Americas. But its foundations are rocked by the death of the most successful pirate who ever lived, Black Sam Bellamy, washed up on a New England beach. But Edward Thatch reinvents himself and becomes the most devilish pirate of all, Blackbeard. Woodes Rogers' campaign begins with the offer of a pardon, which Hornigold and Jennings accept; but not all Nassau pirates agree.