This episode examines the idea of scientific racism, an ideology invented during the 19th century that drew on now discredited practices such as phrenology and provided an ideological justification for racism and slavery. The episode shows how these theories ultimately led to eugenics and Nazi racial policies of the master race.

In this series, we will explore how we can survive Mars. Our species will need to evolve how we eat, drink, and build our homes. In the first episode, humans seem to be on the cusp of reaching Mars, but how did we get to this point? Our journey to our neighboring planet traces a path connecting Nikola Tesla, Nazi weapons of war, a Cold War space race, and a string of blockbuster discoveries made by some of NASA’s most talented robots.

The fifth episode explores how the deportation of Hungary's Jews in 1944 precipitated the most intensive slaughter in Auschwitz's history.

Diarmaid MacCulloch's own life story makes him a symbol of a distinctive feature about Western Christianity - scepticism, a tendency to doubt which has transformed both Western culture and Christianity. In the final programme in the series, he asks where that change came from. He challenges the simplistic notion that faith in Christianity has steadily ebbed away before the relentless advance of science, reason and progress, and shows instead how the tide of faith perversely flows back in. Despite the attacks of Newton, Voltaire, the French Revolutionaries and Darwin, Christianity has shown a remarkable resilience. The greatest damage to Christianity was actually inflicted to its moral credibility by the two great wars of the 20th century and by its entanglement with Fascism and Nazism. And yet it is during crisis that the Church has rediscovered deep and enduring truths about itself, which may even be a clue to its future.

The second episode tells the story of the trial of Hermann Goering, Hitler's charismatic and ruthless second-in-command. On trial for his life at Nuremberg, the unrepentant Reich Marshal turned the tables on the Allies. So much so that Chief Prosecutor Justice Robert Jackson began to wish the Allies had followed Churchill's suggestion and shot the leading Nazis out of hand. This documentary drama traces the behind-the-scenes story of Goering's attempt to re-ignite Nazism from the courtroom.

How did Hitler decide he was a messiah and persuade a whole nation to follow him to damnation? This is a subject that has been mined many times in fiction - Raiders Of The Lost Ark, Constantine, Hellboy, Bulletproof Monk and English horror writer James Herbert's book The Spear - as well as documentary. Based on Ken Anderson's 1995 book of the same name, this aims to show how the Nazi party was originally made up of several occult groups that believed a messiah was on the way to save Germany.