(Click CC for subtitles) Rumors fly about whether an up-and-coming driver will join Hamilton on team Mercedes, potentially leaving Valtteri Bottas without a seat. Seemingly permanently stuck in the crisis of a one-year contract running out, this time Bottas has Mercedes golden boy George Russell breathing down his neck. The young Brit desperately wants Bottas’ seat, and things come to a head when the two collide at Imola. Scandalous.
Bottas can’t resist the inevitable though, and after Russell puts the F1 on the front row at Spa, whilst the Finn can only manage eighth, it looks to be all over. Thus follows a scene of Russell being told he has the Mercedes seat by Wolff in a scene which looks so staged it would make even cringe.

Since the Silverstone GP, it's just gone up and up and up. For Max Verstappen, is kind of do or die. Only a few races remain, and for drivers desperate for any advantage they can get their hands on, the gloves are officially off.

Water plants create some of the most beautiful, bizarre and important habitats on earth. To hold on in torrents, plants use a kind of superglue. Some are armed with vicious weapons to fight titanic battles for space. Others form perfect spheres and escape from animal enemies by rolling. Where nutrients are washed away, plants turn into hunters of animals, laying traps and even counting to ensure their success.
In this episode we explore those watery worlds with David Attenborough, from Croatia to Brazil, from Colombia to Thailand, the brilliantly coloured flowers smother lakes, and in one magical river in Brazil, the water bubbles like champagne as plants create the atmosphere itself.

In the fourth episode, Dromaeosaurs stalk a hadrosaur herd as they cross a freezing river. Male Ornithomimus raid rival nests to bolster their own. Olorotitan raise their offspring on fertile volcanic fields but contend with biting mosquitoes.
Troodontids hunt mammals flushed out by a forest fire. A juvenile Antarctopelta scours the forest for a new winter den. Within the snow-covered forest, a tense standoff develops between ancient rivals, Pachyrhinosaurus and Nanuqsaurus.

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.

When he killed Mehmed’s messengers, it was a message from Vlad Dracula that he would not pay his yearly dues anymore and it was clear that Vlad wanted a war against the Otoman Empire. Mehmed II sends Mara to coax Hungarian King Matthias Corvinus into an alliance. Vlad Dracula’s army was less than 30,000 men, but he invaded Bulgaria and started killing Mehmed’s men in 1462. He stole the Ottomans’ uniforms for his further attacks on the empire. Vlad also destroyed many ports that were under Sultan Mehmed II on the Danube.
Mehmed had to cross the Danube in order to reach the capital city of Târgoviște and defeat Vlad. The sultan faced the challenge of transporting 100,000 men across the river. Along with men, he had to transport cannons and horses too. The first unit to cross the river Danube included Mahmud Pasha, who was the most trusted man of Mehmed II. An epic battle along the Danube River looms, and Vlad has the upper hand.