In the fourth episode of the series, Clovis was the first Frankish king to acknowledge the Christian faith. This changed the direction of Europe's history.

The series concludes by delving into the world of satirical maps. How did maps take on a new form, not as geographical tools, but as devices for humour, satire or storytelling? Graphic Artist Fred Rose perfectly captured the public mood in 1880 with his General Election maps featuring Gladstone and Disraeli, using the maps to comment upon crucial election issues still familiar to us today. Technology was on the satirist's side with the advent of high-speed printing allowing for larger runs at lower cost. In 1877, when Rose produced his 'Serio Comic Map of Europe at War', maps began to take on a new direction and form, reflecting a changing world. Rose's map exploited these possibilities to the full using a combination of creatures and human figures to represent each European nation. The personification of Russia as a grotesque-looking octopus, extending its tentacles around the surrounding nations, perfectly symbolised the threat the country posed to its neighbours.

Examines the impact of racism in the 20th century. By 1900 European colonial expansion had reached deep into the heart of Africa. Under the rule of King Leopold II, the Belgian Congo was turned into a vast rubber plantation. Men, women and children who failed to gather their latex quotas would have their limbs dismembered. The country became the scene of one of the century's greatest racial genocides, as an estimated 10 million Africans perished under colonial rule.

1916. The war is raging in Europe and stretches from the trenches in France to the Italian Alps and the Balkans, and beyond to the gates of the Eastern world. The conflict becomes industrial, and millions of shells rain down on the battlefields; Verdun and the Somme are the deadliest battles in this second year of the war. Who can stop this infernal machine?

With a little imagination, could a few terrorists sabotage a mighty nation? Perhaps even tear down modern civilization? The stability of the US, Europe, China, or any global power depends on high-speed digital communication. Our increasing dependence on digital devices and global interactivity may be placing us in grave danger. Scientists around the world are dealing with new threats such as body hacking, Trojan horse viruses, and brain-damaging Internet addiction. But what if the ultimate threat isn’t an attack on technology, but the technology? Could the final superpower be the disembodied mind of the Internet itself?

This episode examines the end of and the period immediately after World War II. It looks at Stalin's efforts to seize control of Poland and Eastern Europe, Democratic part bosses efforts to drop Henry Wallace from the 1944 presidential ticket, and British efforts to maintain their colonial holdings after the war.