Sir David Attenborough chooses his favorite recordings from the natural world --from the song of the largest lemur to the song of the humpback whale to the song of the lyrebird-- that have revolutionized our understanding of song. The science of song had been transformed by Charles Darwin’s theory of sexual selection: singing is dangerous as it reveals the singer’s location to predators, but it also offers the male a huge reward, the chance to attract a female and pass on genes to the next generation. Today, new science in the field of birdsong is transforming those long-held ideas.
Scientists are discovering that, in fact, in the majority of all songbird species, females sing - and it is only now they are being properly heard. Through this revelation and others, we can understand that animal songs are marvellous examples of the spectacular survival strategies that species have developed.

The film explores the revolutionary gene-editing tech now giving humankind the freedom to redraw the blueprint of biological life itself. We investigate not only the tremendous potential the technology holds, whether in the fight to eliminate diseases or in transforming agriculture to adapt to unprecedented climate extremes, but also probe the inherent risks involved and the potential for widespread abuse, dangers that could take our future down a very dark, dystopian path.

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?

Scientists and engineers fight to save Notre Dame Cathedral after the 2019 fire. When the roof of Notre Dame Cathedral erupted in flames in April of 2019, firefighters battled for nine gruelling hours to save the historic landmark. Still, Paris came alarmingly close to losing more than 800 years of history. Now engineers are in a different race against time: to rebuild the roof and secure the medieval structure of Notre Dame. Underneath the charred scaffolding and vaulted ceilings of the cathedral, scientists study the components of Notre Dame’s iconic structure to puzzle out how best to repair it.

Fearless Nepali high altitude climber Nimsdai Purja embarks on a seemingly impossible quest to summit all of the world's 14 highest peaks with an altitude greater than 8000m (called eight-thousanders) in seven months, breaking by far the previous 7 years record. He named his adventure 'Project Possible.'

The architectural design of Beijing's ancient complex of palaces and temples enabled it to survive centuries of earthquakes. The Forbidden City is the world’s biggest and most extravagant palace complex ever built. For five centuries, it was the power center of imperial China and survived wars, revolution, fires, and earthquakes. How did the Ming Emperor’s workforce construct its sprawling array of nearly 1,000 buildings and dozens of temples in a little over a decade?