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.

For Charley Boorman and Ewan McGregor, their journey in the smooth Ecuadorian roads would most definitely have come as a relief after some rough terrain riding. Next up, they stop by one of the factories that make the famed Panama hats. One of the local producers explains that making them by hand takes roughly up to a month. At the other end, the crew on the Rivians make a dash for Central America where they have to ferry their trucks across as the Darién Gap blocks their path. On their way, they make a quick pitstop at one of the cacao factories to know more about cocoa production, one of the economic drivers of the country.

NASA is on a mission to send humans to Mars within just 15 years, but to reach this next frontier of space exploration, experts must discover new technology and cutting-edge science that protects astronauts from the Red Planet's deadliest killers.

Episode 4 rounds everything out while simultaneously focusing on his career and the next steps. After a performance tribute to Jamal, Ed and Cherry get good news and reflect on a turbulent year.

There's a killer lurking in our galaxy, a star ready to explode into a supernova. Seen from Earth, a supernova in the Milky Wave would have a terrible beauty. But for us, it could be fatal. In a few seconds, it can release as much energy as the sun will over its entire lifetime. It could be anywhere. It is nearly impossible to predict where and when the next supernova will happen. The hunt is on to find the next supernova before it finds us.

A new video pushes panic go to the next level, galvanizing the 'internet nerds' to intensify their own painstaking investigation as police join the hunt. In the previous videos, the object on the bed were cats, in this video, it was an actual person. How hard is it going to be to track him down? How dangerous is this man?