Inside the world-renowned physics laboratory Fermilab, a team of scientists are constructing an audacious experiment to hunt for a mysterious new ‘ghost’ neutrino. If they find it, this could transform our understanding of the nature and fabric of our universe. The problem is, these tiny particles are almost impossible to detect.
Elsewhere, physicists conduct experiments in some of the most extreme environments on the planet: from deep mine shafts in South Dakota to vast ice fields at the South Pole. In these unlikely places supersized neutrino detectors hope to unlock the universe’s deepest secrets. Could neutrinos overturn the most precise theory of particle physics that humans have ever written down? Could they even be a link to a hidden realm of new particles that permeate the cosmos – so called dark matter? Scientists at Fermilab are edging towards the truth.

Just outside Paris, inside a hi-tech vault, and encased in three vacuum-sealed bell jars, rests a small metallic cylinder about the diameter of a golf ball. It may not look like much, but it is one of the most important objects on the planet. It affects nearly every aspect of our lives including the food we eat, the cars we drive, even the medicines we take. It is the Kilogramme, the base unit of mass in the International System of Units. Yet over time, its mass has mysteriously eroded by the weight of an eyelash. A change that, unbeknownst to most, unleashed a crisis with potentially dire consequences.
The film follows the ensuing high-stakes, two-year race to redefine the weight of the world, and tells the story of one of the most important objects on the planet.

In Southeast Alaska, there's an ice-bound Eden that harbors possibly the richest temperate rainforests of all. Where the coastal mountains meet the Pacific, lays the Alexander Archipelago, a remote island chain running for almost 300 miles along the Alaskan Panhandle. This frozen frontier is one of the last great wildernesses of North America. And a stronghold for the country's highest diversity of megafauna, feasting on the abundance of fleeting summers to make it through relentless winters.

At the far tip of South America, lies a magical realm that seems frozen in time. Known as 'the end of the world', this is Patagonia. Vast glaciers shaped it into an Eden like no other. Adaptable and resilient creatures evolved unique survival strategies to flourish across its remarkable habitats. From precipitous mountain citadels and icy desert plateaus windswept steppe uplands through remote, primal forests to a mosaic of glacial valleys. To thrive here is to be as extreme as the land itself.

600 miles off the coast of South America in the Pacific Ocean there are 120 tropical islands that erupted from the deep ocean floor more than 10 million years ago. Journey from the lava ramparts to its fiery heart, we'll discover how the Galapagos archipelago became one of the most important areas of biodiversity in the world.
Those swept here by storms and currents survived million to one odds to find untouched islands free from competition. These hardy pioneers evolved in remarkable ways in what's known as Nature's Greatest Experiment. Home to bizarre specialists and unexpected giants, the most precious collection of island creatures on Earth.

At the very end of East Africa's Great Rift Valley, there's a 'land that time forgot'--the rolling grasslands of the Luangwa Valley. Seemingly untouched plains teem with Africa's most iconic animals. Some are unique to this place, others are critically endangered elsewhere.
Here, prey exist in remarkable balance, each taking advantage of the secret at the heart of this Eden, the mighty Luangwa River and its dramatic annual transformation from dusty inferno to emerald paradise.