Even after thousands of years of ice crushing the northern hemisphere and temperatures of 20 degrees lower than those of today, many of the great giants of the ice age still walked the earth. It was only when the world had warmed up again that mammoths, woolly rhinos, sabre-toothed cats, giant ground sloths and glyptodonts finally became extinct. Professor Alice Roberts sets off on her last voyage back to the Ice Age to discover why.

Dr Jago Cooper reveals the history of some of South America's ancient civilisations. He begins with an epic journey into the remote Peruvian Andes in search of the mysterious Chachapoya people. Once numbering half a million, they were known as the 'People of the Clouds'. Dr Cooper reveals how they developed sophisticated methods of recording stories, traded in exotic goods found hundreds of miles from their territory, and had funeral traditions that challenge assumptions about ancient human behaviour. His search for evidence takes him to astonishing cliff tombs untouched for 500 years and one of the most spectacular fortresses in South America, where the fate of the Chachapoya is revealed.

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.

Series concludes with the focus shifting to the United States in the post-war years of the 1950s and beyond. Beginning with arguably the most notorious work of 20th century classical music, John Cage's 'silent' composition 4'33", it looks at how a series of maverick Americans re-invented the sound of classical music into a more simple form, bringing back harmonies and rhythms that made it increasingly popular with audiences across the world. It also examines how this music found its way into a spiritual realm, with the strain of pared-down religious composition that came to be known as 'holy minimalism'. From the Maverick concert hall in Woodstock, New York to an Orthodox cathedral in Estonia to a car park in Peckham, south London, the story is told by a stellar line-up of contributors including Philip Glass, Steve Reich, John Adams, Arvo Pärt and John Tavener.

East Africa is a land which is constantly changing. To survive here, creatures must be able to deal with unpredictable twists and turns - wet turning to dry, feast to famine, cold to hot - no matter how hostile it becomes. From dense forests to snow capped peaks, steamy swamps and endless savannah, this unique and varied land is also a haven for life, supporting large animals in numbers found nowhere else on Earth. But away from the familiar, forever-travelling herds, there are a huge cast of other characters - lizards that steal flies from the faces of lions, vast dinosaur-like birds who stalk catfish through huge wetlands, and an eagle who risks everything on the arrival of ten million bats from a far off rainforest.

Many movies lend themselves to dramatic interpretations, but none are as rich and far ranging as Stanley Kubrick's The Shining. In LA filmmaker Rodney Ascher's ROOM 237, we hear from people who have developed far-reaching theories and believe they have decoded the hidden symbols and messages buried in the late director's film. Carefully examining The Shining inside out, and forwards and backwards, and backwards and forwards, ROOM 237 as captivating, provocative as it is pure pleasure". It gives voice to the fans and scholars who espouse these theories, reworking the film to match their ideas and intercutting it with layers of dreamlike imagery to illustrate their streams of consciousness. Sometimes outrageous, always engaging, the words of those who were interviewed are given full force by Ascher's compelling vision. Also featured at the 2012 Sundance, Cannes and Toronto film festivals.