This episode is centered around how science, in particular the work of Clair Patterson (voiced in animated sequences by Richard Gere[33]) in the middle of the 20th century, has been able to determine the age of the Earth. Tyson first describes how the Earth was formed from the coalescence of matter some millions of years after the formation of the Sun, and while scientists can examine the formations in rock stratum to date some geological events, these can only trace back millions of years. Instead, scientists have used the debris from meteor impacts, such as the Meteor Crater in Arizona, knowing that the material from such meteors coming from the asteroid belt would have been made at the same time as the Earth. Patterson also examined the levels of lead in the common environment and in deeper parts of the oceans and Antarctic ice, showing that lead had only been brought to the surface in recent times. He would discover that the higher levels of lead were from the use of tetraethyllead in leaded gasoline resulting in government-mandated restrictions on the use of lead.

The constellation of the Pleiades provides a vehicle for us to explore a series of paradoxes and epochal discoveries for humanity. The untold story of the modern "sisters of the sun," the early 20th century female astronomers, led by two deaf women, at Harvard who catalogued the stars. It's also the story of the young British woman who joined forces with them, her defiance of the world's leading expert, and how she taught the world what the stars are really made of.

This episode explores the palaeogeography of Earth over millions of years, and its impact on the development of life on the planet. Tyson starts by explaining that the lignin-rich trees evolved in the Carboniferous era about 300 million ago, then explains on the nature of plate tectonics that would shape the landmasses of the world and the asteroid impact that initiated the Cretaceous–Paleogene extinction event, leaving small mammals as the dominate species on earth. Earth's landmasses are expected to change in the future and postulates what may be the next great extinction event.

Among the ranks of the Wehrmacht there was limited opposition to Hitler. Most officers initially felt enthusiastic about the prospect of war and were grateful to Hitler whose war-mongering had furthered their personal careers. Furthermore all soldiers had to make an oath of allegiance to the Führer and, up until the very end, there were many who felt unable to break this pledge. There were, however, some officers who opposed Hitler. For some it was on moral grounds and for others because they thought that his military tactics would lose them the war. There were plots against Hitler and attempted coups, the best known being the July bomb plot led by Claus von Stauffenberg. Some soldiers refused to bear arms and were shot, others deserted, others still carried out quiet acts of sabotage and subversion. By and large, however, the Wehrmacht carried out the orders Hitler issued, even if it involved perpetrating acts of atrocity.

The determination of the German forces to keep on fighting in the face of defeat had disastrous consequences. After the Allied landings in the summer of 1944, the Wehrmacht was on the defensive on all fronts. It was clear to the German generals interned at Trent Park that Germany would soon lose the war. In mid-1944, Gerhard Graf von Schwerin chose to use common sense instead of blindly obeying Hitler's orders. He decided to surrender the city of Aachen to the US army to avoid bloodshed. Other commanders such as Field Marshal Ferdinand Schorner kept on pushing their soldiers to give their all. Despite being outnumbered by the Soviet forces, Schorner forced his soldiers to hold out in Sworbe, a 200 square kilometre peninsula on the coast of Estonia. Thousands of soldiers died. Yet Schorner's attitude and the urging by Hitler and Goebbels to hold out were accepted by a large number of young soldiers. By April 1944, the Ruhr pocket was completely surrounded, yet Field Marshal Model refused to surrender, so that 1.2 million German soldiers and a large number of Allied soldiers died between January and May 1945.

This is the story of three maps, three 'visions' of London over three centuries. The Morgan Map of 1682 was the first to show the whole of the City of London after the Great Fire of London. In 1746 John Rocque produced at the time the most detailed map ever made of London. Like Morgan's, Rocque's map is all neo-Classical beauty and clinical precision, but the London it represented had become the opposite. In engravings of the time, such as Night, the artist William Hogarth shows a city boiling with vice and corruption. Stephen Walter's contemporary image, The Island, plays with notions of cartographic order and respectability. His extraordinary London map looks at first glance to be just as precise and ordered as his hero Rocque's but, looking closer, it includes 21st century markings such as 'favourite kebab vans' and sites of 'personal heartbreak'.