The final episode begins with a description of the extreme cold conditions that characterized the beginning of the Holocene period, and how species like the bison and the wolf adapted to survive in these hostile environments. We will witness the majesty of the woolly mammoth and the fierce cave lion, with a vivid reconstruction of their struggles for survival. We'll see the impact of climate change during this period, from the expansion of the deserts to the transformation of the tropical rainforests of Africa into grasslands, deeply affecting primates and other animals. It highlights how these changes forced primates to adapt to life on the ground, facing new challenges and predators.
A crucial turn occurred with the emergence of humans as dominant predators and their influence on the extinction of large mammals. The documentary describes humanity's transition from hunter-gatherers to farmers, a change that radically altered the landscape and biodiversity of the planet. Finally, it poses a reflection on the current challenges of climate change and the sixth mass extinction, inviting viewers to consider humanity's crucial role in shaping the future of the Earth.

David Attenborough explores Britain and Ireland’s grasslands, revealing the creatures that create them and the extraordinary stories they hide. From the coastal flower meadows in the Scottish Outer Hebrides to the rich open landscapes in the mountains of southern Ireland, we enter surprising and dramatic worlds.
In southern England, we meet an extraordinary bee that lives in chalk grassland, one of our rarest habitats, laying her eggs in empty snail shells. Meanwhile, in the colourful machair of the Hebrides, ringed plovers and lapwings strive to rear their families of tiny fluffy chicks and to save them for marauding gulls.
We travel back in time to explore the vast wild grasslands once found throughout our isles, before meeting herds of semi-wild horses, where males battle fiercely for the females. Today, they are helping to turn some of this land back to wilderness. And in our precious remaining pockets of flower-rich meadow, a remarkable conservation success story plays out. Once extinct in our isles, England now has the largest known populations of large blue butterflies. Their survival relies on a game of deception with red ants, which are tricked into adopting the butterfly’s unassuming but predatory caterpillars.
Our story then journeys to the mountains. Each morning in early spring, feisty male black grouse battle for prime position on their frozen breeding grounds. Their sole mission is to impress a female. Meanwhile, on south-facing scree slopes, dozens of adders emerge from hibernation to perform a surprisingly delicate courtship routine.
The episode concludes with a mighty battle in the wild mountains of County Kerry. This is the scene of an epic and spectacular rut between the largest land mammals in Britain and Ireland, red deer.
The grasslands of Britain and Ireland are under threat. We have lost 97 per cent of our species-rich meadows in the last century, as modern agriculture replaces these precious habitats. This episode shows just how important different types of grassland are to the species which call these islands home.