A hero is just someone who acts selflessly, out of concern for others, at personal risk and without the expectation of reward. In this episode, Michael Stevens asks employees to help him run a seemingly dangerous experiment, to see if they would blow the whistle to stop him.

The end is coming. But which cosmic catastrophe will deliver the death blow? Were the Vikings right to fear the frozen apocalypse of an endless winter? Did the Buddhists correctly predict a fiery end to life on Earth? Or will the thunderous Christian vision of Armageddon come crashing down from the stars? Which ancient prophesy do scientists believe accurately foretells our doom? And how close are we to the end of the world?
This film explores all the possibilities Apocalyptic Visions to the Future.

Astrology, the celestial movements of the Sun, Moon, and planets among the stars, governing our personality and destiny. For centuries, millions of people, from paupers to powerful world leaders, have relied on the ancient system for answers. This episode examines whether tracking astronomical phenomena can actually predict the future.

Inside the heart of the atom, its nucleus houses energy. This hidden treasure was forged billions of years ago in distant stellar furnaces. The secret of starlight is nothing to fool with. It can bring a civilization to life and it can burn it to the ground.
Two atoms from different parts of the universe meet on a small planet. A deadly embrace between science and state altered the fate of the world and a gripping cautionary tale of others who grew used to living in the shadow of grave danger until it killed them all except one.

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.

The final episode of this series looks at what happens to the brain when someone uses psychedelic drugs. It looks at how psychedelic drugs may be useful in dealing with anxiety in cancer survivors and serious depression. It explores the history of psychedelics and examines early medical experimentation with the drug. It also discussed why psychedelics were banned and examines how they affect the brain.