A team of Australian and Chinese scientists discover mysterious ancient human remains from a remote cave in South West China. The bones are unlike any living human or any ancient human known to science, yet they were alive at the same time as humans of our own kind. Could they represent a new human species? And if so, what happened to these people?

Japan's landscapes range from snowy mountains to subtropical warmth. They are full of wildlife - and animals' and people's lives often cross as they adapt to these extremes. The central island of Honshu is home to over 100 million people, and its biggest city, Tokyo, is one of the largest urban metropolises on earth. But it has a wild heart - most of Honshu is mountainous. This wilderness is home to an astonishing range of wildlife - black bears, monkeys, exquisite fireflies and even cow demons. But all across this island, from the mountains to the edge of the sea, people and nature are drawn together in the most unexpected ways.

In the far south west of Japan, there is a chain of islands stretching towards the tropics - a place where all life is influenced by the power of the sea, and where volcanoes and typhoons are forces to be reckoned with. The journey begins at an island at the top of the chain and travels south, revealing unexpected stories of isolation, unique wildlife and unsolved mysteries.

Al-Khalili travels to northern Syria to discover how, a thousand years ago, the great astronomer and mathematician Al-Biruni estimated the size of the earth to within a few hundred miles of the correct figure. He discovers how medieval Islamic scholars helped turn the magical and occult practice of alchemy into modern chemistry. In Cairo, he tells the story of the extraordinary physicist Ibn al-Haytham, who helped establish the modern science of optics and proved one of the most fundamental principles in physics - that light travels in straight lines. Prof Al-Khalili argues that these scholars are among the first people to insist that all scientific theories are backed up by careful experimental observation, bringing a rigour to science that didn't really exist before.

On the coast, two worlds collide. Coasts are the most dynamic and challenging habitats in the ocean - that brings great rewards but also great danger. The extraordinary animals that live here must find ingenious ways to cope with two very different worlds. This episode is a rollercoaster ride of heart-stopping action and epic drama, peopled with characters from the beautiful to the bizarre. We meet fish that live on dry land and puffins that must travel 60 miles or more for a single meal, and witness a life-and-death struggle in a technicolour rock pool. In a secluded cove in the Galapagos, sea lions feast on 60kg tuna. It should be impossible - tuna are usually far too fast for sea lions to catch. But here the sea lions club together to herd their prey inshore. Once trapped in the shallows, these huge fish are easy pickings. As the tide recedes in Brazil, lightfoot crabs leap from rock to rock, desperately avoiding the water - their lives depend on it. Moray eels launch themselves from rock pools, jaw gaping. Then octopuses, too. Both crawl across dry rock to set their ambush. Elsewhere, the ever-changing tides create rock pools. But these temporary worlds are a battleground. Predatory starfish turn a magical garden into the stuff of nightmares.

Discover our extraordinary world through a stunning cinematic experience— -following the journeys of acclaimed photographers pursuing their personal projects. Their aim: changing people's perceptions through art. From the art of sacred nature, to the demons of the deep and the juxtaposition of life and death. Over the years Eric Cheng has dived with the planet's most magnificent creatures. Now he is determined to use his photography to tell the true story of the most misrepresented and demonised species.