In the third programme of the series, Aleks gives the lowdown on how, for better and for worse, commerce has colonized the web - and reveals how web users are paying for what appear to be 'free' sites and services in hidden ways. Joined by some of the most influential business leaders of today's web, including Eric Schmidt (CEO of Google), Chad Hurley (CEO of YouTube), Bill Gates, Martha Lane Fox and Reed Hastings (CEO of Netflix), Aleks traces how business, with varying degrees of success, has attempted to make money on the web. She tells the inside story of the gold rush years of the dotcom bubble and reveals how retailers such as Amazon learned the lessons. She also charts how, out of the ashes, Google forged the business model that has come to dominate today's web, offering a plethora of highly attractive, overtly free web services, including search, maps and video, that are in fact funded through a sophisticated and highly lucrative advertising system which trades on what we users look for. Aleks explores how web advertising is evolving further to become more targeted and relevant to individual consumers. Recommendation engines, pioneered by retailers such as Amazon, are also breaking down the barriers between commerce and consumer by marketing future purchases to us based on our previous choices. On the surface, the web appears to have brought about a revolution in convenience. But, as companies start to build up databases on our online habits and preferences, Aleks questions what this may mean for our notions of privacy and personal space in the 21st century

In the fifth episode of the series, lavish imperial games at the Colosseum are highlighted by the emperor's bloody victories, but his paranoid abuses of power lead to a final betrayal.

In the fourth episode, leading landscape photographer Peter Eastway follows in the footsteps of Frank Hurley – the pioneering Australian photographer on Shackleton’s expedition to the south a century ago – to capture the wilderness and wildlife of Antarctica and South Georgia.

With increasing rumours of a pending arrest intensified, the Bhagwan flees the ranch. The two Learjets carrying Rajneesh and ten of his followers lands at the Charlotte airport, where U.S. police were waiting for them. The United States Marshals Service arrests Rajneesh. Almost simultaneously, Sheela and several followers are also arrested in Germany. In a federal court in Portland, Bhagwan Shree Rajneesh pleads guilty to immigration fraud charges and agrees to leave the country. The Bhagwan's devotees -- and his enemies -- reflect on his legacy.

The final part examines political revolution and how art was at the forefront of throwing out 1,000 years of royal rule, from its earliest revolutionary days of enthusiasm and optimism when painting died, the poster was king and the machine-made triumphed over the handmade to the dead hand of Socialist Realism. Andrew roots out great portraits of Stalin now hidden in museum storerooms and never on public view, looks at the transformation of the Moscow metro into a great public art gallery and visits the most stunning creation of post-war Communist rule, the Space Monument. Finally, he comes to the confusion and chaos of Russia today and how it is producing some of the world's strangest art - from heroic sculptures of Russian leader Vladimir Putin to the insides of a giant erotic apple; from the recreation of the Imperial royal family facing the firing squad to sculpture in liquid oil; from Russia's embrace of the commercial art market to a return to Socialist Realism. Russia seems to stand on another brink of revolution.

Carl Sagan teaches students in a classroom in his childhood home in Brooklyn, New York, which leads into a history of the different mythologies about stars and the gradual revelation of their true nature. In ancient Greece, some philosophers (Aristarchus of Samos, Thales of Miletus, Anaximander, Theodorus of Samos, Empedocles, Democritus) freely pursue scientific knowledge, while others (Plato, Aristotle, and the Pythagoreans) advocate slavery and epistemic secrecy.