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.'

Ewan and Charley make their way to Peru from Bolivia, and the scenery is just beautiful. Ewan wanted to visit Machu Picchu since he was a kid and decides to show the world the Incan citadel set high in the Andes Mountains. Next up, they make their way to the Cutivireni, a community of Ashaninka people in the Amazon rainforest, with its carbon program to limit the magnitude or rate of global warming and its related effects.

Virgilio Martínez is the chef/owner of Central, a restaurant in Lima, Peru that currently sits at number four on the World’s 50 Best Restaurants list. After a decade spent cooking in kitchens around the world, Martínez only found his true identity as a chef when he began exploring the different regions of his native Peru, from the ocean to the Andes. While some chefs are obsessed with a 'sense of place,' Martínez strives to offer his guests a sense of many places — entire ecosystems over the course of a tasting menu.
Martínez always had an adventurous spirit, but growing up in Peru during the 70s and ‘80s meant that many parts of the country were closed off to him. As a teenager, he learned that pursuing a career in the kitchen would allow him the freedom to travel all over the world. The chef ended in charge of a restaurant in Madrid. This is really where Virgilio started to develop his experimental style. Martínez decided to leave Spain to go and work on opening his own restaurant in Peru. He decided to explore the idea of cooking dishes based on altitudes and ecosystems. Martínez runs Central’s kitchen with his wife, Pia León. They developed the altitude-based menu concept together. Martínez’s sister, Malena, has a science background, so he brought her on as part of the team to explore different terrains in search of ingredients that they could use at the restaurant. Virgilio remarks: 'We use 180 ingredients, and 50 percent of them are unknown.' The altitude-themed tasting menu was introduced in 2012, and the following year, Central landed at the bottom of the World’s 50 Best Restaurants list. Two years later, it soared to number four.

A documentary thriller about the world of cyberwar. For the first time, the film tells the complete story of Stuxnet, a piece of self-replicating computer malware (known as a worm for its ability to burrow from computer to computer on its own) that the U.S. and Israel unleashed to destroy a key part of an Iranian nuclear facility, and which ultimately spread beyond its intended target. This is the most comprehensive accounting to date of how a clandestine mission hatched by two allies with clashing agendas opened forever the Pandora's Box of cyberwarfare.

In episode two, Professor Brian Cox is off to India, where he assesses arguably the first evidence of rational thought in literature, the poetry of the Vedic monks. They pondered mankind's origins, realising there must have been a day with no yesterday - a day of creation - prompting the age-old question of where did the universe come from? Brian marvels that the universe seems to follow a set of rules, the laws of physics, allowing space to be considered on the grandest scale, travelling to the most distant, farthest reaches of the cosmos just by using our minds. Brian also visits Japan, and offers viewers the idea that man lives in just one of an infinite number of universes that are being made all the time.

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.