An examination of the heavy metal music subculture that tries to explain why, despite the longevity and popularity of the genre, fans are marginalized and ridiculed for their passion.
Sam Dunn is a anthropologist and a lifelong metal fan. After years of studying diverse cultures, Sam turns his academic eye a little closer to home and embarks on an epic journey into the heart of heavy metal. His mission: to figure out why metal music is consistently stereotyped, dismissed and condemned, even while the tribe that loves it stubbornly holds its ground -- spreading the word, keeping the faith and adopting styles and attitudes that go way beyond the music.
Sam visits heavy metal landmarks as far flung as L.A.'s Sunset Strip, the dirty streets of Birmingham and the dark forests of Norway. Along the way, the two sides of Sam Dunn -- curious anthropologist and rabid fan -- collide, as Sam explores metal's obsession with sex, religion, violence and death, meets his heroes, and discovers some things about the culture that even he can't defend.

Every summer in the seas off Alaska humpback whales, sea lions and killer whales depend on an explosion of plant life, the plankton bloom. It transforms these seas into the richest on Earth. But will these animals survive to enjoy the great feast? The summer sun sparks the growth of phytoplankton, microscopic floating plants which can bloom in such vast numbers that they eclipse even the Amazon rainforest in sheer abundance of plant life. Remarkably, it is these minute plants that are the basis of all life here. But both whales and sea lions have obstacles to overcome before they can enjoy the feast. Humpback whales migrate 3,000 miles from Hawaii, and during their 3 month voyage lose a third of their body weight. In a heart-rending scene a mother sea lion loses her pup in a violent summer storm, while another dramatic sequence shows a group of killer whales working together to kill a huge male sea lion.
In late summer the plankton bloom is at its height. Vast shoals of herring gather to feed on it, diving birds round the fish up into a bait ball and then a humpback whale roars in to scoop up the entire ball of herring in one huge mouthful. When a dozen whales work together they employ the ultimate method of co-operative fishing - bubble net feeding. One whale blows a ring of bubbles to engulf the fish and then they charge in as one. Filmed from the surface, underwater and, for the first time, from the air, we reveal how these giant hunters can catch a tonne of fish every day.

Every year grizzly bear families in North America depend for their survival on a spectacular natural event: the return of hundreds of millions of salmon from the Pacific Ocean to the mountain streams where they were born. The salmon travel thousands of miles to spawn and then die. The great run not only provides food for bears, but for killer whales, wolves, bald eagles, and even the forest itself. The question is: will the salmon return in time to keep hungry bears alive?
A mother grizzly and her cubs emerge from their den high in snowy Alaskan mountains. Filming from the air the team capture a TV first, following the bears as they negotiate a near vertical slope on their journey to the coast where they await the return of the salmon. Meanwhile, the salmon are making their way to the to river mouths where they must swim upstream and against the current. The programme reveals how they tackle the torrents and leap over waterfalls, a feat equivalent to a human jumping over a house. Dozens of hungry bears eagerly await the salmon that make it up river. In another TV first, underwater cameras record the ingenuity and fancy footwork they use to collect dead salmon from the bottom of deep pools.

About 340 million years ago a brand new family of animals was evolving in the primeval swamps. They were to go one step further than the amphibians who had emerged onto dry and before them. For they would eventually completely cut their ties with water. They were the ancestors of todays lizards. They evolved scaly impermeable skins and moved up into the forests. They diversified into a multitude of different shapes and sizes. They developed signalling systems to communicate with one another. And they squabbled as animals do. For food they hunted insects that were already well established on the land in great numbers. And here without returning to water they produced their families. They powered their bodies not only with food but with the heat that they drew directly from the sun.
As they diversified so they spread into the harshest of the lands habitats. The baking waterless deserts which eventually they would come to dominate. Discover jacky lizards that wave, wrestling beaded lizards and the the world's smallest chameleon, which is no bigger than his thumbnail, and the biggest lizard in Australia.

The Sundarbans mangrove forest, in Bangladesh near the Indian border, is a tidal jungle where Ganges and Brahmaputra enter the Indian Ocean. Its has some 400 Bengal tigers - the largest population in the world, and the only to be hardly scared of men. The downside is tigers kill up the 50 Bangladeshis a year, even from neighbouring villages, so keeping them inside the reserve is key to long-term survival.
A recent project tries to train local mongrels, not pets but fiercely self-reliant dogs, to spot and even scare off tigers from villages. An individual tiger can turn into a man-eater in order to survive - this process may occur due to an injury or old age (and so cannot hunt agile prey) or even accidentally tasting human flesh.

Buddhists, Hindus, and hundreds of thousands of travellers from around the globe flock to Cambodia every year to experience the grandeur of Angkor. Its famous temples were built over the span of five centuries by the rulers of the Khmer Empire, and endure today as one of Earth's greatest archaeological wonders. Join us as we shed light on one of the most enigmatic, mesmerizing civilizations in the history of mankind. We peel away the myth and legend to uncover the hidden story behind the creation of this ancient city.
Angkor Wat is the largest temple on the face of the Earth and is a symbol of one of the greatest empires in the history of Southeast Asia. And yet, for centuries, the sacred structure remained lost within the tropical forests of Cambodia, along with the history of the young king who built the temple. Discover the story of Suryavarman II and how he ushered in the golden age of the Khmer Empire. See how Angkor Wat was constructed over four backbreaking decades, and witness the monument in its true glory and splendour, as it appeared 900 years ago.