Explore the breathtaking extremes of our planet in this captivating episode. Journey through the vast Hang Son Doong cave in Vietnam, the largest on Earth. Witness the resilience of life in harsh conditions, marvel at the adaptation strategies of species like the blind cave fish and the enduring Arctic wolf pack. In the Arctic, observe the strategic hunt of wolves preying on musk oxen, a dance as old as the Ice Age. In the French Alps, the struggle for mating among common frogs unfolds, showcasing the urgency and challenges faced by cold-blooded animals. Witness the social dynamics of Barbary macaques in the cedar forests of the Atlas Mountains, where survival hinges on social bonds. The forests of Mexico, home to millions of monarch butterflies that huddle for warmth, illustrates the fragility and beauty of nature.
Discover how fire shapes ecosystems in South Africa's fynbos and Northern Australia, crucial for the survival of species like the golden-shouldered parrot. The documentary poignantly addresses the impact of changing climates and human intervention on wildlife, from the endangered elephants of Amboseli, Kenya, to the secretive snow leopards of the Gobi Desert. This episode offers a profound glimpse into the extraordinary adaptations and challenges faced by wildlife across the globe, reminding us of the delicate balance and beauty of life on Earth.

Can skyscrapers be made safer, more efficient, and livable in our rapidly growing cities? Skyscrapers are gleaming symbols of prestige, and an ingenious way to save space in dense urban areas. But as buildings rise ever higher, what are the risks of these architectural behemoths?
Do we truly know how they will hold up in earthquakes, fires and wind? What have--or haven’t—we learned from past tragedies? But even as we devise ways to defend them against potential disasters, can we also make them more livable, interactive, and eco-friendly?

Three years after the devastating fire, Lucy Worsley has exclusive access to the Cathedral of Notre-Dame de Paris at a key turning point of the restoration. Work to rebuild and restore the monument is being ramped up in a bid to meet the ambitious deadline to reopen it to the public in 2024. Scaffolding now fills the interior of the cathedral, giving Lucy and the team unprecedented close-up access to every inch of the structure. Lucy meets scientists, historians and craftspeople working to return the 850-year-old Gothic masterpiece to its former glory.
The fire coated Notre-Dame with tons of toxic lead dust, so specialists are now decontaminating the site. Unique access to the stunning rose windows allows Lucy and the stained-glass historians to uncover the mysteries of these enigmatic 13th-century works of art. An unforeseen legacy of the fire threatens to destroy the remaining vaulting, so the team must develop an ingenious solution to save the stonework. The loss of the roof during the fire reveals hundreds of large iron staples embedded in the stone along the top of the walls. And the incredible task of sourcing and cutting two-thousand perfect oaks gets underway to rebuild the world's most complex medieval timber structure - Notre-Dame's extraordinary roof and spire.

Will explore the strategy, deception and feats of engineering plants use to thrive in the changing weather of different seasons. In the face of conditions ranging from ice and snow to raging fires, survival is often a question of perfect timing - particularly when contending with intense competition and surprising predators.
In this episode, David Attenborough travels to Finland to show one of the most extreme examples of seasonal plant life in the Arctic Circle. He also travels to California to see how climate change is affecting giant sequoias. These ancient trees like all other seasonal plants depend on the predictability of the seasons and our current changing climate threatens their survival.

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 last episode, Austroposeidon level trees in search of fresh foliage. A herd of Triceratops journey through a cave to find an underground clay lick. A male Carnotaurus sets the stage for an extravagant display. A female Qianzhousaurus uses an autumn storm to her advantage while hunting Corythoraptor.
A family of Edmontosaurus evade a forest fire, while an Atrociraptor and Ankylosaur reap its rewards. Juvenile Therizinosaurus attempt to climb up to a bee nest. Hatzegopteryx hunts Zalmoxes, and patrols the dense undergrowth and seaspray-battered coastline.