Travelling from K2 in Pakistan to Ladakh in India. It is a short distance as the crow flies but, due to politics, a huge loop. He passes through the Sikh city of Amritsar, with its Golden Temple, and through Shimla with its Vice Regal Lodge, Gaiety Theatre and cosy half-timbered tea-houses. He then meets the 14th Dalai Lama in Dharamsala, where the Tibetan government is in exile.

In the Land of the Cave Bear, Alice ventures to the parts of the northern hemisphere, hit hardest by the cold - Europe and Siberia. High in the mountains of Transylvania, a cave sealed for thousands of years reveals grisly evidence for a fight to the death between two staving giants, a cave bear and a cave lion. Yet Alice discovers that for woolly rhinos and woolly mammoths, the Ice Age created a bounty. The Mammoth Steppe, a vast tract of land which went half way round the world, provided food all year round, for those that liked the cold. It was these mammoths that Europe's most dangerous predators hunted for their survival.

This episode explores the nature of the greenhouse effect (discovered by Joseph Fourier and Svante Arrhenius), and the evidence demonstrating the existence of global warming from humanity's influence. Tyson begins by describing the long-term history of the planet Venus; based on readings from the Venera series of probes to the planet, the planet had once had an ocean and an atmosphere, but due to the release of carbon dioxide from volcanic eruptions, the runaway greenhouse effect on Venus caused the surface temperatures to increase and boiled away the oceans. Tyson then notes the delicate nature of the amount of carbon dioxide in the atmosphere can influence Earth's climate due to the greenhouse effect, and that levels of carbon dioxide have been increasing since the start of the 20th century. Evidence has shown this to be from mankind's consumption of oil, coal, and gas instead of from volcanic eruptions due to the isotopic signature of the carbon dioxide. The increase in carbon dioxide has led to an increase in temperatures, in turn leading to positive feedback loops of the melting polar ice caps and dethawing of the permafrost to increase carbon dioxide levels. Tyson then notes that humans have discovered means of harvesting solar power, such as Augustin Mouchot's solar-driven motor in the 19th century, and Frank Shuman's solar-based steam generator in the 1910's. Tyson points out that in both cases, the economics and ease of using cheap coal and oil caused these inventions to be overlooked at the time. Today, solar and wind-power systems would be able to collect enough solar energy from the sun easily. Tyson then compares the motivation for switching to these cleaner forms of energy to the efforts of the Space race and emphasizes that it is not too late for humanity to correct its course.

Volcanoes are one of nature’s most awesome and destructive forces, but they are also the life force and architect of our planet. They can raise up great mountains and create new land, or they can level cities and destroy entire civilizations. They provide a glimpse of the power of Earth’s internal heat source, without which it would have become a dead planet millions of years ago. In this episode, Iain takes us on a journey to some of the most dramatic places on Earth, starting in Ethiopia.

Part 2 examines how the freewheeling modernism that had shocked audiences in the first two decades of the century came under state control. Initially, many practitioners thought the totalitarian regimes would be good for music and the arts. What followed in Germany was a ban on music written by Jews, African-Americans and communists, while in the Soviet Union there was a prohibition on music the workers were unable to hum. After the cataclysm of the 1940s, a new generation of composers - Boulez, Stockhausen, Xenakis, Nono, Ligeti - turned their back on what they saw as the discredited music of the past and tried to reinvent it from scratch. Or, at least, from serialism, which became as much of a straitjacket as totalitarianism's strictures had been. But from this period of avant-garde experimentation, which many listeners found baffling and terrifying, came some of the most influential and radical musical innovations of the century.

In the second stop in his exploration of the wonders of the universe, Professor Brian Cox goes in search of humanity's very essence to answer the biggest questions of all: what are we? And where do we come from? This film is the story of matter - the stuff of which we are all made. Brian reveals how our origins are entwined with the life cycle of the stars. But he begins his journey here on Earth. In Nepal, he observes a Hindu cremation. Hindu philosophy is based on an eternal cycle of creation and destruction, where the physical elements of the body are recycled on to the next stage. Brian draws a parallel with the life cycle of the stars that led to our own creation. Next, he explains how the Earth's resources have been recycled through the ages. How every atom that makes up everything we see, was at some time a part of something else. Our world is made up of just 92 elements, and these same 92 elements are found throughout the entire universe. We are part of the universe because we are made of the same stuff as the universe.