Huge asteroids have smashed into the earth, and turned it into an enveloped fire, uninhabitable to almost all life on the surface. The world will get hit again. It's just a matter of when. So, what should we do as a species? Should we just, like the dinosaurs, look up and die? The reasons the dinosaurs are extinct is they didn't have a space program. We do. We have the capability to perhaps escape the Earth.
Astronaut Chris Hadfield believes the only chance for human survival is to escape from Earth and build a space colony, but there are real barriers.

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?

A heroic congressman, Leo Joseph Ryan Jr, travels to Jonestown; some Temple members plot their escape. Jim Jones realizes the walls are closing in and plans his final stand. After the massacre, the world learns about mass murder/suicide in Jonestown, orchestrated by cult leader. Survivors try to piece their lives back together.

Autistic minds provide windows into how we all think, feel, and behave. A complete brain science should be able to account for all kinds of minds and brains. As long as some minds remain a mystery, so too will all minds.
Michael Stevens travels to London to meet a blind, autistic savant with astonishing musical abilities, and volunteers to have his brain's function temporarily disrupted at UCLA's Neuromodulation Lab.

The search for climate change solutions requires passion, resources and a sense of urgency -- three qualities Bill Gates clearly possesses. Bill has founded a start-up called TerraPower. After extensive computer modelling, the idea showed promise. Its new reactor greatly reduced the chance of human error. Fuelled by depleted uranium, the travelling wave reactor functions like a slow-burning candle and requires refuelling only once every decade. Bill and his team believed they had finally developed the ideal energy source, a reactor that was clean, efficient, and most importantly, safe.

Episode 3 continues to show the obstacles faced with charging electric bikes in remote places, but Ewan McGregor and Charley Boorman start to learn and evolve their process. The risk of cold temperatures is high but they bravely do it anyway. The duo is having a hard time of it out there but, thankfully, the scenery is absolutely stunning. Heading through Patagonia, Ewan and Charley stay at an eco-lodge in one of the world’s remotest areas with people that live off the grid.