The fourth episode starts off with the two riding through Santa Cruz, Argentina. The plan is to cross over into Chile and then going up into the Andes. Ewan and Charley head through Argentina’s red rock landscape while a member of their team copes with altitude sickness. The duo are well and truly underway and the first signs of all are well is how well the Harleys hold up in challenging conditions. The roads alternate between unforgiving and pleasant and these e-bikes push through effortlessly. As they ride through Chilean Andes, the audience is shown a picturesque view of the beauty of the countryside, an experience which Boorman calls 'magical.'

The written word is so important in everyday life that there can be few more radical acts than forcing an entire nation to learn a new script. Yet that is what happened in Turkey in 1928 when Mustafa Kemal decreed that the Arabic script would be replaced by the letters of the Latin alphabet. Communication with computers using human language is usually made with Latin letters. This is how most Chinese people interact with their computers and smart phones, using a Latin-based phonetic script called Pinyin. As a result, even highly educated Chinese are losing the ability to write using Chinese characters. Could what is happening in China be the future of writing everywhere?

Writing itself is 5,000 years old, and for most of that time words were written by hand using a variety of tools. The Romans were able to run an empire thanks to documents written on papyrus. Scroll books could be made quite cheaply and, as a result, ancient Rome had a thriving written culture. With the fall of the Roman Empire, papyrus became more difficult to obtain. Europeans were forced to turn to a much more expensive surface on which to write: Parchment. Medieval handwritten books could cost as much as a house, they also represent a limitation on literacy and scholarship.
No such limitations were felt in China, where paper had been invented in the second century. Paper was the foundation of Chinese culture and power, and for centuries how to make it was kept secret. When the secret was out, paper mills soon sprang up across central Asia. The result was an intellectual flourishing known as the Islamic Golden Age. Muslim scholars made discoveries in biology, geology, astronomy and mathematics. By contrast, Europe was an intellectual backwater.
That changed with Gutenberg’s development of movable type printing. The letters of the Latin alphabet have very simple block-like shapes, which made it relatively simple to turn them into type pieces. When printers tried to use movable type to print Arabic texts, they found themselves hampered by the cursive nature of Arabic writing. The success of movable type printing in Europe led to a thousand-fold increase in the availability of information, which produced an explosion of ideas that led directly to the European Scientific Revolution and the Industrial Revolution that followed.

The last episode of the series talks about the most important city in the States. Stories that go from the early 40s until today. Interviews with Rick Rubin, Emmylou, Chris Martin, LL Cool J and Barack Obama. And a real statement about what is happening with the studios business nowadays. The song 'I Am A River' is recorded during this episode.

NASA's brand-new Mars rover is on the hunt for alien life, and with the help of cutting-edge engineering, scientists embark on a search for fossilized remains, which might prove the Red Planet was once home to a vast ocean and extraterrestrial life. Perseverance carries seven scientific instruments to study the Martian surface at Jezero crater. It carries several cameras and two microphones. The rover is accompanied by the helicopter Ingenuity, which will help Perseverance to scout for locations to study.

This second instalment looks at how Vladimir Putin arrived in the Kremlin as a vulnerable and unknown president, whom the Russian oligarchs expect to control. The programme reveals how he asserted his hold on power and ultimately surrounded himself with his KGB peers, as well as his philosophy as regards traitors and enemies. The film also examines the stories of businessman Boris Berezovsky and defector Alexander Litvinenko, who both stood up to Putin and wound up dead on British soil.