Following the Yangtze along Tiger Leaping Gorge into Yunnan in China, Palin reaches the easternmost end of the Himalayas. He gets a medical check-up before exploring medieval Lijiang with the director of the local orchestra. Heading over Myanmar to Nagaland in India he rides the steam train to Tipong Coalmine. In Assam he rides an elephant and then stays in a strange monastery.

In Bhutan, Palin finds himself back in the land of yaks for a last look at the high Himalaya. Trekking to Chomolhari base camp he meets a nomad with a penchant for yak songs before heading down to Paro to witness the Buddhist festival or Tsechu. In a bar in Thimphu, he discusses reincarnation and the pursuit of happiness with Benji and Khendum, two of the king's cousins, and en route to Bangladesh is taken by Benji to see the rare black-neck cranes. On his journey south through Bangladesh, Michael visits the ship-breaking beaches of Chittagong and grid-locked Dhaka. He meets a man who made a fortune in Birmingham in the poultry business, and a woman who lends money only to women. On a 1920s paddle steamer he is serenaded with the words of Bengal's Shakespeare, and he completes his epic Himalayan journey aboard a fishing boat that carries him out into the Bay of Bengal and a westering sun.

Director James Cameron returns to the site of the 1912 wreck of the RMS Titanic. With a team of history and marine experts he embarks on an unscripted adventure back to the final grave of 1,517 people. Using two small, purpose-built remotely operated vehicles, we can see inside the Titanic and with the help of CGI, view the ship's original appearance superimposed on the deep-dive images. Throughout the movie, there are re-enactments of events that are discussed that use CGI recreations of the interior of the Titanic. The documentary was named one of the Best 3D movies ever by Rolling Stone.

The magnificent ancient city of pyramids at Caral in Peru is a thousand years older than the earliest known civilisation in the Americas and, at 2,627 BC, is as old as the pyramids of Egypt. Many now believe it is the fabled missing link of archaeology - a 'mother city'. If so, then these extraordinary findings could finally answer one of the great questions of archaeology: why did humans become civilised?" For over a century, archaeologists have been searching for what they call a mother city. Civilisation began in only six areas of the world: Egypt, Mesopotamia, India, China, Peru and Central America. In each of these regions people moved from small family units to build cities of thousands of people. They crossed the historic divide, one of the great moments in human history. Why? To find the answer archaeologists needed to find a mother city - the first stage of city-building. Caral, is so much older than anything else in South America that it is a clear candidate to be the mother city. It also is in pristine condition. Nothing has been built on it at all. Instead laid out before the world is an elaborate complex of pyramids, temples, an amphitheatre and ordinary houses. Scientists developed a number of theories. Some said it was because of the development of trade, others that it was irrigation. Some even today believe it was all because of aliens. Gradually an uneasy consensus emerged. The key force common to all civilisations was warfare. Crucially, there is not the faintest trace of warfare at Caral; no battlements, no weapons, no mutilated bodies. Instead, Ruth's findings suggest it was a gentle society, built on commerce and pleasure. In one of the pyramids they uncovered beautiful flutes made from condor and pelican bones. They have also found evidence of a culture that took drugs and perhaps aphrodisiacs. Most stunning of all, they have found the remains of a baby, lovingly wrapped and buried with a precious necklace made of stone beads.

The documentary 'The Knowledge of Healing' is an illuminating examination of Tibetan medicine, a practice which has developed over two millennia into a modern day successful method of healing that rivals western medical practices. Unlike Western medicine, based on biochemistry, Tibetan medical thinking (which is strongly rooted in Buddhist principles) views the human body as governed by an elaborately organized system of energies flowing through a network of channels. In the 12th century, the Gyüshi (Knowledge of Healing) was created, a text codifying this intricate system. The medications used comprise herbs, roots, minerals, etc. After flourishing for centuries, most Tibetan medical schools were destroyed by the Chinese in the 1950's and 1960's, and many physicians were executed. Speaking from exile, the Dalai Lama argues for the value of Tibetan medicine, while his personal physician Dr. Tenzin Choedrak describes the principles behind it. We follow physicians in India and Siberia treating patients for a variety of ailments from paralysis to heart disease, and meet researchers in Israel and Switzerland to see how western clinical studies are testing the effectiveness of Tibetan medicine.

Sagan discusses comets and asteroids as planetary impactors, giving recent examples of the Tunguska event and a lunar impact described by Canterbury monks in 1178. It moves to a description of the environment of Venus, from the previous fantastic theories of people such as Immanuel Velikovsky to the information gained by the Venera landers and its implications for Earth's greenhouse effect. The Cosmos Update highlights the connection to global warming.