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.

In astronomy, we've been looking at different kinds of light and opening up the universe a little bit more of the time. But then in 2015, the roof came off. Something happened that changed everything, the ability to see waves in space and time itself. Gravitational waves help us roll back the clock to the dawn of time, discover epic cosmic collisions, on make Earth-shaking discoveries. Gravitational waves are the biggest game changer since the invention of the telescope. We have a completely new universe to view now. A new exploration of space is just beginning.

The second episode is about how plants gain their sustenance. Sunlight is one of the essential requirements if a seed is to germinate, and Attenborough highlights the cheese plant as an example whose young shoots head for the nearest tree trunk and then climb to the top of the forest canopy, developing its leaves en route. Using sunshine, air, water and a few minerals, the leaves are, in effect, the "factories" that produce food. However, some, such as the begonia, can thrive without much light. To gain moisture, plants typically use their roots to probe underground. Trees pump water up pipes that run inside their trunks, and Attenborough observes that a sycamore can do this at the rate of 450 litres an hour — in total silence. Too much rainfall can clog up a leaf's pores, and many have specially designed 'gutters' to cope with it. However, their biggest threat is from animals, and some require extreme methods of defence, such as spines, camouflage, or poison. Some can move quickly to deter predators: the mimosa can fold its leaves instantly when touched, and the Venus flytrap eats insects by closing its leaves around its prey when triggered. Another carnivorous plant is the trumpet pitcher that snares insects when they fall into its tubular leaves. Attenborough visits Borneo to see the largest pitcher of them all, Nepenthes rajah, whose traps contain up to two litres of water and have been known to kill small rodents.

Even 2,000 years after his death, General Hannibal's battle strategies are still studied today. But of all his military feats, perhaps his greatest was leading his massive Carthaginian army of men and three-dozen elephants across the Alps and into the heartland of Rome in 218 B.C. Until now, the route they took has been a matter of dispute, but thanks to modern-day technology, geomorphologist Bill Mahaney and microbiologist Chris Allen believe they've accurately traced this ancient journey.

An intimate portrait of Malala Yousafzai, who was wounded when Taliban gunmen opened fire on her and her friends' school bus in Pakistan's Swat Valley. The then 15-year-old teenager, who had been targeted for speaking out on behalf of girls' education in her region of Swat Valley in Pakistan, was shot in the head, sparking international media outrage. An educational activist in Pakistan, Yousafzai has since emerged as a leading campaigner for the rights of children worldwide and in December 2014, became the youngest-ever Nobel Peace Prize Laureate.

The story of the longest surviving and certainly the loudest genre of rock, heavy metal. With no sign of disappearing, metal has been the most controversial and misunderstood of all rock genres. With Black Sabbath as the undisputed Godfathers, we follow their highs and lows, and, along the journey, meet Deep Purple, Judas Priest, Iron Maiden and Metallica.