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.

Our universe is at war. The universe is a very violent and deadly place. Entire galaxies fight to the death. Only the strongest survive. If a galaxy wants to stay alive, it has to feed on other galaxies. Our own galaxy also fights for survival. These battles are how galaxies live, grow, and die. These collisions got us to where we are today, and they're going to determine the future of the universe.

Ten years after waging a bloody campaign to gain control over his own province, powerful samurai warlord Oda Nobunaga has seized much of Central Japan, including the nation’s capital, Kyoto. Now, driven by a towering ambition, he dreams of crushing the powerful clans who still oppose his rule. And for the first time in over a century, uniting all of Japan under one banner. But Nobunaga’s legendary brutality has caused widespread anger. Across the nation, powerful enemies now plot his demise.

Nicholas felt enormous pressure to continue the dynasty and expand the empire. He saw his opportunity in the Far East. This brought him into conflict with a rising power, Japan. Russia's disastrous war against Japan prompts civil unrest. The birth of Prince Alexei is incredibly important. He's the long-awaited son that they had hoped so much for. But when Alexei is diagnosed with haemophilia, Siberian mystic Rasputin steps in. He's very good at realizing when something is open that will enable him to increase his power and wealth. The pressure of keeping the secret of Alexei's illness affects the political decisions that Nicky and Alix made for the rest of their reign.

An unassuming 80-year-old device that has the appearance of a typewriter could actually be one of the greatest secret weapons in history. Using cutting-edge digital technology, experts investigate the secrets of a revolutionary encryption machine.
How could there be a carving of a modern helicopter on an ancient Egyptian inscription? can this 800-year-old device covered in strange sayings really predict the future?

The series showcases what happened in 1993 in Waco, Texas when cult leader David Koresh faced off against the federal government in a siege of 51 days. In the first episode, gunfire erupts when federal agents arrive at the Branch Davidian compound with a search warrant. Hostage negotiators later attempt to get the children out of the compound.
David Koresh was a member and later a leader of the Branch Davidians, a religious sect and offshoot of the Davidian Seventh-day Adventists, a movement based at the Mount Carmel Center outside Waco, Texas. His apocalyptic Biblical teachings attracted various followers. He became subject to allegations about polygamy and child sexual abuse by former Branch Davidian associates, although investigation by authorities found no conclusive evidence. Further allegations related to the Branch Davidians' stockpiling of weapons led the FBI to launch a raid on the group's Mount Carmel compound in February 1993.