The series concludes by delving into the world of satirical maps. How did maps take on a new form, not as geographical tools, but as devices for humour, satire or storytelling? Graphic Artist Fred Rose perfectly captured the public mood in 1880 with his General Election maps featuring Gladstone and Disraeli, using the maps to comment upon crucial election issues still familiar to us today. Technology was on the satirist's side with the advent of high-speed printing allowing for larger runs at lower cost. In 1877, when Rose produced his 'Serio Comic Map of Europe at War', maps began to take on a new direction and form, reflecting a changing world. Rose's map exploited these possibilities to the full using a combination of creatures and human figures to represent each European nation. The personification of Russia as a grotesque-looking octopus, extending its tentacles around the surrounding nations, perfectly symbolised the threat the country posed to its neighbours.

Our planet has amazing power, and yet that's rarely mentioned in our history books. This series tells the story of how the Earth has influenced human history, from the dawn of civilisation to the modern industrial age. It reveals how geology, geography and climate have been a far more powerful influence on the human story than has previously been acknowledged. A combination of epic story telling, visually stunning camerawork, extraordinary locations and passionate presenting combine to form a highly original version of human history" In the first episode professor Iain Stewart explores the relationship between the deep Earth and the development of human civilisation. He visits an extraordinary crystal cave in Mexico, drops down a hole in the Iranian desert and crawls through seven-thousand-year-old tunnels in Israel. His exploration reveals that throughout history, our ancestors were strangely drawn to fault lines, areas which connect the surface with the deep interior of the planet. These fault lines gave access to important resources, but also brought with them great danger.

There's something very odd going on in space - something that shouldn't be possible. It is as though vast swathes of the universe are being hoovered up by a vast and unseen celestial vacuum cleaner. Sasha Kaslinsky, the scientist who discovered the phenomenon, is understandably nervous: 'It left us quite unsettled and jittery' he says, 'because this is not something we planned to find'. The accidental discovery of what is ominously being called 'dark flow' not only has implications for the destinies of large numbers of galaxies - it also means that large numbers of scientists might have to find a new way of understanding the universe. Dark flow is the latest in a long line of phenomena that have threatened to rewrite the textbooks. Does it herald a new era of understanding, or does it simply mean that everything we know about the universe is wrong?

By our third year, most of us will have learned to count. Once we know how, it seems as if there would be nothing to stop us counting forever. But, while infinity might seem like an perfectly innocent idea, keep counting and you enter a paradoxical world where nothing is as it seems. Mathematicians have discovered there are infinitely many infinities, each one infinitely bigger than the last. And if the universe goes on forever, the consequences are even more bizarre. In an infinite universe, there are infinitely many copies of the Earth and infinitely many copies of you. Older than time, bigger than the universe and stranger than fiction. This is the story of infinity.

Iain sets sail on one of the fastest racing boats ever built to explore the story of our turbulent relationship with the wind. Travelling to iconic locations including the Sahara desert, the coast of West Africa and the South Pacific, Iain discovers how people have exploited the power of the wind for thousands of years. The wind is a force which at first sight appears chaotic. But the patterns that lie within the atmosphere have shaped the destiny of continents, and lie at the heart of some of the greatest turning points in human history.

Iain explores man's relationship with fire. He begins by embarking on an extraordinary encounter with this terrifying force of nature - a walk right through the heart of a raging fire. Fire has long been our main source of energy and Iain shows how this meant that the planet played a crucial role in Britain's industrial revolution, whilst holding China's development back. Along the way he dives in a mysterious lake in Oregon, climbs a glacier of salt, crawls through an extraordinary cave in Iran and takes a therapeutic bath in crude oil.