The episode, devoted to the planet Mars, begins with scientific and fictional speculation about the Red Planet during the late nineteenth and early twentieth centuries (H. G. Wells' The War of the Worlds, Edgar Rice Burroughs' science fiction books, and Percival Lowell's false vision of canals on Mars). It then moves to Robert Goddard's early experiments in rocket-building, inspired by reading science fiction, and the work by Mars probes, including the Viking, searching for life on Mars. The episode ends with the possibility of the terraforming and colonization of Mars and a Cosmos Update on the relevance of Mars' environment to Earth's and the possibility of a manned mission to Mars.

The terrorist group Boko Haram is responsible for thousands of deaths in Nigeria. Now, the government is determined to drive these militants from the country. But is the hunt for insurgents causing as much harm as it's preventing? Former Navy SEAL and new VICE correspondent Kaj Larsen travels to Nigeria to see what this cat-and-mouse game means for the people caught in the middle of the fight. 'Unnatural Selection': For centuries, scientists have been working to change the genetic traits of plants and animals. Now, the new gene-editing method CRISPR has made that process astonishingly simple - so simple it could easily be used on humans. Isobel Yeung reports from Brazil, Scotland, China and the U.S. on the technological advances that could reshape evolution as we know it.

As the journey continues, there's beauty and danger in equal measure. Charley and Ewan travel through the extraordinary Bolivian desert, but the sandy roads make all more difficult. The duo ride their electric bikes through the exotic and breathtaking countryside and all the way making a challenging ascent. The riders stay in a hotel made entirely out of salt before heading to La Paz. 'Bolivia' also shows some quality work done by UNICEF when it comes to educating and working with the children. McGregor and Boorman spend time with the kids before resuming their journey and ending with a ferry ride over lake Titicaca.

Filmmaker Jonathan Reiss offers a multilingual look at the evolution of graffiti in a documentary that begins by examining ancient rock paintings and traces the trend straight through to the works of Picasso and 1970s-era New York City hip-hop culture. Shot on five continents using guerilla filmmaking techniques, Bomb It aims to give viewers a newfound appreciation of graffiti culture by exploring the origins of street art and interviewing the artists about their tactics and motivations.

The world knows Britney Spears: performer, artist, icon. But in the last few years, her name has been publicly tied to another, more mysterious term: conservatorship. Britney vs Spears tells the explosive story of Britney’s life and her public and private search for freedom. Featuring years-long investigative work, exclusive interviews and new documents, this featured film paints a thorough portrait of the pop star’s trajectory from girl next door to a woman trapped by fame and family and her own legal status.
Director Erin Lee Carr and journalist Jenny Eliscu work to delve deep into the tangled history of Britney's conservatorship and investigate her legal fight by way of exclusive interviews and confidential evidence.

We have become too comfortable in societies that are immensely wasteful. As a consequence across the globe, the natural world about us is now suffering from the waste we throw away. Is it possible for us to keep what we have and continue to progress without generating waste? This film will expose the root causes of our wastefulness, highlight people around the world working on incredible solutions and it willl introduce you to the new projects shortlisted for the fifth goal of the Earthshot Prize.