In this final episode we complete our journey, travelling back from the March equinox to the end of June. Kate Humble is in the Arctic at a place where spring arrives with a bang, whilst Helen Czerski chases a tornado to show how the earth's angle of tilt creates the most extreme weather on earth.

The next great voyage of human exploration has already begun: the search for life on planets orbiting distant stars. With extraordinary CGI, the world's most inspiring scientists, via extreme environments on Earth and around the solar system, the film takes viewers aboard the next generation of space ships, across the cosmos and beneath the clouds of the exo-planets to discover The Living Universe.
Part 1: 'The Planet Hunters' For as long as we’ve had eyes to see and minds to wonder we’ve marveled at the stars. Since the discovery of the first so-called exoplanet in 1994, the Planet Hunters have transformed the way we see the universe. It is the year 2157, and spacecraft Artemis enters the final phase of construction.

What connects amateur sleuths turning up at crime scenes, anti-social behaviour in schools and riots? Marianna Spring has spent one year investigating harmful behaviour on TikTok spilling out into the real-world. As well as crunching the numbers, Marianna tracks down TikTok users, victims and former employees to interrogate and expose how extremely high engagement on TikTok around particular topics appears to be creating these 'frenzies'.
The documentary explores how users go to extreme lengths in order to get more engagement in a battle for followers and likes. Marianna investigates the role TikTok's algorithm and format plays in what’s happening and reveals insiders’ concerns about the app. The film seeks to find out if this is the real danger and what impact it is having on society.

We all project images of ourselves online - a curated identity that defines how we want to be perceived. But what temptations exist to embellish and what are the dark implications? In this episode, enter the world of Cyberbanging, where inner city youth are using social media to brag, conspire and incite violence; two African-American women bloggers who have turned the table on the trolls who threaten them; and the creator of Abdullah X, an online character who's trying to keep Muslim kids from falling under the spell of Islamic extremists.

Here, Aleks charts how the Web is forging a new brand of politics, both in democracies and authoritarian regimes. With contributions from Al Gore, Martha Lane Fox, Stephen Fry and Bill Gates, Aleks explores how interactive, unmediated sites like Twitter and YouTube have encouraged direct action and politicised young people in unprecedented numbers. Yet, at the same time, the Web's openness enables hardline states to spy and censor, and extremists to threaten with networks of hate and crippling cyber attacks.

The Great Pyramids of Giza remain one of the enduring wonders of the ancient world. This mesmerizing monument have eluded astronomers and archeologists for centuries. Why and how the ancient pyramids of the pharaohs were built? Were they merely burial tombs, or a cosmic vehicle to the celestial world? What were the motives and methods behind the orientation of the pyramids to face the four cardinal directions with extreme accuracy?
The world's renowned Egyptologists, astronomers and engineers join forces to solve some of the long-held mysteries about the pyramids.