The world's deserts are lands of extremes that force animals to come up with ingenious ways of coping with hostile conditions, giving rise to the most incredible survival stories on earth. A pride of desert lions are so hungry they risk hunting a giraffe several times their size, while male sandgrouse fly 120 miles each day to the nearest waterhole and dice with death to collect water for their chicks. Filmed for the first time, a tiny bat does battle with one of the world's deadliest scorpions, and in Madagascar, a locust swarm of biblical proportions is seen as never before.

Cities are growing at a faster rate than any other habitat on Earth. They may seem an unlikely place for animals to thrive, but they can be a world of surprising opportunity. Leopards prowl the streets of Mumbai, peregrine falcons hunt amongst New York's skyscrapers, and a million starlings perform spectacular aerial dances over Rome. In Jodhpur, langurs are revered as religious deities and in Harar, locals live in harmony with wild hyenas. Many animals, however, struggle to cope in the urban jungle. As the architects of this environment, can humans choose to build cities that are homes for both them and wildlife?

In the third episode, the discovery of extraterrestrial life might face an impossible challenge: the physics of the universe itself; but using cutting-edge tech, experts might be on the verge of a groundbreaking find -- and the evidence could already be in hand.

The Caribbean is home to a notorious band of British pirates called the Flying Gang. They plunder merchant ships, sailing from the Americas to Europe and Africa. England's King George I has had enough, so he comes up with a shock tactic to end piracy. It's an offer from the King, a pardon, clemency for those who turn their backs on piracy. Those who refuse will be hunted down and hanged. Two pirates, Blackbeard and Charles Vane stand the King's man, Woodes Rogers. Who will win the final battle?

Astronomers make an extraordinary discovery out in deep space when they uncover a cosmic mega-structure that's one billion light-years long. Now, investigators race to decode the hidden forces that shape the most massive and mysterious structure known in the Universe.
We dive into this space great wall's fiery birth and hunt for the weird cosmic glue that holds it together to reveal how this megastructure rewrites our understanding of the universe on an epic scale.

Garrett McNamara recovers from the injuries he sustained at Mavericks and begins training to return to Nazaré for another season. While surfing at Indonesia's G-Land site, Garrett suffers more injuries that threaten to take him off the waves permanently. Meanwhile, a friend of Garretts catches an 80-foot wave at Nazaré, taking the world record from McNamara. McNamara resolves to continue his hunt for a 100-foot wave.