Dr Hannah Fry travels down the fastest zip wire in the world to learn more about Newton's ideas on gravity. His discoveries revealed the movement of the planets was regular and predictable. James Clerk Maxwell unified the ideas of electricity and magnetism, and explained what light was. As if that wasn't enough, he also predicted the existence of radio waves. His tools of the trade were nothing more than pure mathematics. All strong evidence for maths being discovered.
But in the 19th century, maths is turned on its head when new types of geometry are invented. No longer is the kind of geometry we learned in school the final say on the subject. If maths is more like a game, albeit a complicated one, where we can change the rules, surely this points to maths being something we invent - a product of the human mind. To try and answer this question, Hannah travels to Halle in Germany on the trail of perhaps one of the greatest mathematicians of the 20th century, Georg Cantor. He showed that infinity, far from being infinitely big, actually comes in different sizes, some bigger than others. This increasingly weird world is feeling more and more like something we've invented. But if that's the case, why is maths so uncannily good at predicting the world around us? Invented or discovered, this question just got a lot harder to answer.

Morgan Freeman travels the world to study the cycles of war and peace. From the ritualized combat of the sacred Tinku festival in Bolivia to Rwanda's post-genocide reconciliation program, this episode deals with humanity's enormous capacity for violence and the endless pursuit of harmony. Conflict can drive innovation, but is war necessary?

The nervous system is fundamentally electric. When we move our arm, it moves because a electric signal has been sent to the muscle that controls it. Now, because the brain is electric, we could also use electricity to record what the brain is doing or bypass it entirely, and control a body. That means that we could restore movement to people who are paralyzed, feel through an artificial hand as if it was our own, and even read people's minds.
Michael Stevens explores how electricity can be used to move cockroaches, control other peoples' limbs and even read peoples' thoughts.

When the followers of the Indian so-called 'guru of sex', Bhagwan Shree Rajneesh, start to build a utopian city in the Oregon desert, a massive conflict with local ranchers ensues; producing the first bioterror attack in US history, the largest case of illegal wiretapping, and the world's biggest collection of Rolls-Royce automobiles.
In the first episode, under the watchful eye of his secretary, Ma Anand Sheela, spiritual leader 'Osho' moves his ashram from India to Oregon in 1981.

Ma Anand Sheela and several other followers recount their experiences of moving to the ranch and the hostility from the residents of the city of Antelope. With the help of architects, engineers, city planners and commune residents, Rajneeshees construct a town called Rajneeshpuram. The commune decides to become self-governing which would allow them to issue their own building permits and have separate law enforcement.
Locals describe their mistrust towards Bhagwan. The American press begins to affiliate Rajneeshpuram with the Jonestown Massacre and paints Bhagwan as an antichrist. The group '1000 Friends of Oregon' initiates a court case to have the buildings of Rajneeshpuram destroyed. In response, Sheela begins buying up available properties in Antelope.

Ma Anand Sheela emerges as a provocative spokeswoman. The Rajneesh control Antelope city council and they establish a police force in the city. Bhagwan tells Sheela it is time to control Wasco County. As Election Day approaches, the Rajneeshees recruit thousands of homeless people to fortify their ranks.