In the second episode, Andrew Carnegie builds an empire around steel, but finds himself struggling to save face after the ruthless tactics of his business partner, Henry Frick, result in both the Johnstown Flood as well as the bloody 1892 strike at the Homestead Steel Works.

Pluto is one of the Smaller than our own Moon, Pluto has never had a single visitor from Earth - until now. We keep saying, 'This is it, this is humanity's trip to Pluto. For the first time in human history, Pluto is about to be revealed. We can expect surprises, it's almost guaranteed. Until then, we can only guess what Pluto looks like. And recently, astronomers decided not to call it a planet any more. Once thought to be an isolated oddity, Pluto now marks the beginning of a whole new frontier. it's as if the explorers had climbed up to the top of the Rockies and were looking over and could see the lands of California on the other side. There has never been a better time to venture where no human has gone before. To follow in the footsteps of our robot pioneers and explore beyond the planets of our Solar System.

The most famous – and perhaps most misunderstood – episodes in the epic history of the Holy Wars that are known to history as The Crusades – the clash between Richard the Lionheart and Saladin. In July 1192, Richard the Lionheart stood poised for a strike on Jerusalem, while Saladin – mighty sultan of Islam – readied his troops inside the city, preparing for the inevitable attack. During a year-long campaign across Palestine, these two legendary leaders had fought each other to a stand-still. Thousands had perished, appalling atrocities had been perpetrated on both sides. And now they faced each other in a battle for their sacred objective.

In the second episode, Nathan develops a rehearsal for Angela, a woman considering motherhood. Nathan hires child actors to simulate adopting and caring for a baby and sets her up in a rented farmhouse in rural Oregon. Due to Oregon child protection laws, Nathan's team must covertly switch out the baby every four hours and replace it with a robot baby at night. Seeking a simulated husband, Angela dates Robbin, a numerology-obsessed man who wants to have sex with Angela despite her devout Christian beliefs against premarital sex. When Robbin quits the project due to the robot baby's incessant crying, Nathan inserts himself into the experiment as Angela's non-romantic co-parent.

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.

Travelling forward in time to 30,000 years ago, it's the middle of an ice age. The landscape is dominated by mighty mammoths, living side-by-side with woolly rhinos, giant deer and two separate species of human. The programme follows the fate of a herd of mammoths in their annual struggle against the harsh ice-age conditions. Every summer they spend on the grassy plains of what will one day become the bottom of the North Sea, but every winter they are forced to head for the less exposed valleys further south. It is a journey fraught with danger: mammoths can get trapped in frozen bogs, and the herd must run the gauntlet of hunters like cave lions and the deadly Neanderthals.