In the Taurus Mountains Simon stays with descendants of the original Turks, nomads known as Yoruks, whose lifestyle is under threat from the modern world and an increasingly religious government. They're not the only minority at odds with the authorities in Turkey; Simon sees first-hand the devastating effects of fighting in the country's Kurdish region. In an area where the government has detained foreign journalists, Simon gathers unique footage in the aftermath of a crackdown on Kurdish militants - the wholesale destruction of the historic centre of one of Turkey's oldest cities.
Away from the conflict in the south, Simon heads towards the Black Sea coast. He meets a wildlife conservationist protecting Turkey's population of brown bears, and villagers who still communicate over long distances using an ancient bird language. In the country's capital he meets a victim of President Erdogan's authoritarian purge of people accused of complicity in the failed coup against him.
Finally Simon's journey comes full circle when he returns to Istanbul - home to the new craze of 'Ottomania', a celebration of the vast empire that preceded modern Turkey. Simon visits the set of one of the world's most popular TV dramas - even getting a speaking role - based in the court of an Ottoman sultan

At the top of our planet lies a magical realm, the Arctic Ocean. After four months of winter darkness, the sun returns to reveal a frozen ocean covered in ice. Mother polar bears emerge from their hillside dens and lead their cubs down to the sea ice to hunt, while a young male and female bear forge a surprising friendship out on the ice.
For others, the frozen sea is a trap. A pod of beluga whales has been confined to an ice hole for five months, slowly starving to death as the food around them runs out. Their salvation lies in the strengthening sun that comes with spring, melting the sea ice, allowing their escape.
Off the east coast of Greenland, the floating pack ice in spring is a nursery ground for harp seals. Mothers and pups have just a few weeks together for the pup to learn to swim before she leaves him to fend for himself. But in today’s warming climate, storms can tip helpless youngsters into the sea before they are strong enough to fend for themselves.
Summer is a time of plenty in the Arctic Ocean as plankton blooms feed millions of tiny mouths, such as bizarre skeleton shrimps, as well as the biggest: bowhead whales. These ancient and long-lived whales arrive en masse every year at secret locations known as whale spas. But today, with the loss of summer sea ice, their peace is shattered by orcas from the south. These daring predators are bold enough to take on the much larger bowheads, targeting their vulnerable calves.
The 24-hour daylight of the Arctic summer attracts visitors from afar, including huge flocks of seabirds like crested auklets. A male must use both his song and a secret tangerine perfume if he is to attract a mate. For the resident walrus, the summer heat can be unbearable. After hauling himself to the beach to moult, an old male uses an ingenious technique to get himself back to the cool of the water - a roly-poly!
Summers in the Arctic today bring record-breaking heat. With climate change, it is warming faster than anywhere else on Earth. It is predicted that the Arctic Ocean could become ice-free each summer by 2035, raising new challenges for polar bears. Without sea ice, more and more bears are becoming stranded on remote Arctic islands. It's a dangerous place to be for a mother bear with cubs, surrounded by larger, predatory males.

In the far north of our planet lies the largest land habitat on earth, home to snow-covered forests and the icy open tundra. These are lands of extremes that push animals to their limits: in winter they are so cold that much of the ground has remained frozen since the last ice age. To stand any chance of survival, animals must adapt in extreme ways: here a super pack of wolves, 25 strong, has come together to take on the only large prey available to them in winter, American bison.
On the featureless tundra, an Arctic fox must strike a living alone. She is a wanderer and will roam many hundreds of miles searching for tiny lemmings, hidden deep underground. The only way to reach them is with a head dive. In the remote far east of Russia, a rare Amur leopard prowls the seemingly empty, snow-covered forest. With little prey available, it must use its ingenuity to find a meal. It follows crows in the hope of finding carrion, but it must not stay long, for it shares the forest with a far larger but equally hungry big cat, the Siberian tiger.
As spring arrives, the forests begin to thaw and life returns. Beneath the ground, a nest of tiny painted turtle hatchlings now emerge, having remained frozen in a state of suspended animation throughout winter. To the north, it is a further month before the sun’s warmth baths the frozen ground of the tundra. Tucked away underground lies a tiny snow queen – a Lapland bumble bee. She is the sole survivor of her colony - the rest perished in the winter freeze - but her larger size, her furry body and antifreeze in her blood have allowed her to survive. Now she is in a hurry. She must feed herself and raise a brood in the brief window of summer while the flowers are in bloom.
Snowy owls also use the open tundra to breed: one pair have raised a nest full of fluffy chicks. With 24-hour daylight in which to hunt, the dedicated parents bring back meal after meal for their ever-growing brood. But one day, they return to find the nest empty.
Today, the biggest challenge in the tundra is climate change. Warming summers are melting the permafrost deep within the soil, causing the ground to thaw and, in places, the land to collapse. These changes are impacting the animals too. Caribou arrive in herds of 200,000 individuals to raise their calves in the rich pastures, but warming means mosquitos emerge sooner and bother the calves before they have had a chance to gain strength. The parents drive their young to cooler, mosquito-free land, but to get there they must cross rivers running with increased meltwater and escape hungry grizzly bears. They, like much of the tundra's wildlife, are adapted to live in the extremes - but the challenge of today’s warming climate could be one extreme too many.

Our frozen planet is changing. In this final episode, we meet the scientists and people dedicating their lives to understanding what these changes mean, not just for the animals and people who live there, but for the world as a whole.
Our journey begins in the Arctic, where every summer huge quantities of ice calve from the edges of Greenland’s melting glaciers. On top of the ice cap itself, glaciologist Alun Hubbard descends into a moulin to try to understand the mechanisms that are driving this historic loss of ice.
Elsewhere in the Arctic, it’s not just land ice that is disappearing. In the Gulf of St Lawrence, Canada, biologists are trying to find out how the loss of sea ice will impact the lives of baby harps. In Arctic Russia, with the loss of summer sea ice, more and more polar bears are arriving on the island of Wrangel. Here, a local ranger and scientists are braving the hungry bears to assess their future survival.
Loss of sea ice impacts not just wildlife but people too. In the remote community of Qaanaaq, Greenland, local Inuit hunters are finding the ice too dangerous to travel and hunt on, risking their traditional way of life. And these changes happening in the Arctic have the potential to affect people far beyond. On Alaska’s open tundra, bubbling lakes hint at the gases being released from the previously frozen soil, including the potent greenhouse gas methane.
There is one place where the full scale of a melting Arctic can be best witnessed - from space. Based in the International Space Station, astronaut Jessica Meir looks down at forest fires across Europe and reflects how our changing weather patterns are interconnected.
Rapid ice loss is also happening across the high mountains of the planet’s continents. Glaciologist Hamish Pritchard uses a sophisticated helicopter-strung radar system to try to quantify how much ice is left in the previously uncharted glaciers of the Himalayas. It’s important as, downstream, some 1.2 billion people rely on glacial meltwater as their primary source of fresh water.
Finally, in Antarctica, we meet Bill Fraser, who has dedicated 45 years of his life to studying the Adelie penguin. Over this period, he has witnessed changes in weather conditions and the extinction of entire colonies. These ‘canaries in the coal mine’ are a sign that all is not well, even in the remotest place on earth. And changes here have the potential to affect all of us, so an international group of scientists is on an urgent mission to assess the stability of a huge body of ice known as the Thwaites ice shelf. If this plug of ice melts and slips into the ocean, it will raise global sea levels, impacting coastal communities across the planet.
The unprecedented changes our scientists are witnessing may be profound, but there is hope that, through a combination of technology and willpower, there is still time to save what remains of our frozen planet.

Chris turns to longevity doctor Peter Attia to find out how changing his eating habits can help his quest for longevity. Ironically, the answer is to eat no food at all for four long days. If he can bear the hunger, fasting will unlock his body’s own anti-aging powers and give Chris the edge he needs when he tries to hunt for his next meal … by spearfishing off the Great Barrier Reef.

Predators and prey are in an arms race for survival. Hunters and hunted deploy hidden super- skills in the battle to eat or be eaten. Masterclasses in predatory perfection are vital to passing on skills. So when they're ready to hunt for real, the next generation is fully prepared for the battle between predator and prey.
Life is a mission, survival. Animals have evolved secret weapons and hidden skills to outsmart their enemies. So in those life or death moments, it takes the most extraordinary super powers to prevail.