In the last episode of the series, lavish imperial games at the Colosseum are highlighted by the emperor's bloody victories, but his paranoid abuses of power lead to a final betrayal.

From a 2,400-year-old corpse in remarkable condition to how shrunken heads are made, these 15 ancient secrets will have you completely riveted. The Vesuvius eruption may have been a gradual process. It took a storm to lift the cover on this ancient Roman city. The people of Pompeii often resorted to vigilante justice. How the wealthy of Pompeii protected their valuables? Was this pre-Viking gathering a prelude to a massacre? The valuable commodity behind King Solomon's wealth. This valuable Viking grave is missing something important. Is this where humanity decided to settle down? This mysterious stone structure is older than Stonehenge. This 2,400 year old corpse is in remarkable condition. Here's exactly how shrunken heads are made. DNA analysis reveals troubling news about shrunken heads. This mass grave discovery could alter Roman history. Gladiator teeth reveal signs of infant malnourishment. Evidence suggests Stonehenge was an elite cemetery.

With optional Hebrew subtitles. This episode explores how the spread of the Enlightenment brought ghetto walls around Europe crashing down and allowed Jews to join the wider fabric of modern life in Europe in unprecedented ways. This Jewish renaissance saw Giacomo Meyerbeer and Felix Mendelssohn to establish the enduring tradition for Jewish musical prodigies. However the integration of Jewish talent into the mainstream of European culture and commerce eventually stirred up ancient prejudice, expressed in the new fashion of Romantic nationalism and the pseudo-science of anti-semitism.

Tyson begins the episode by explaining the nature of the speed of light and how much of what is seen of the observable universe is from light emanated from billions of years in the past. Tyson further explains how modern astronomy has used such analyzes via deep time to identify the Big Bang event and the age of the universe. Tyson proceeds to describe how the work of Isaac Newton, William Herschel, and James Clerk Maxwell contributed to understanding the nature of electromagnetic waves and gravitational force, and how this work led towards Albert Einstein's Theory of Relativity, that the speed of light is a fundamental constant of the universe and gravity can be seen as distortion of the fabric of space-time. Tyson describes the concept of dark stars as postulated by John Michell which are not visible but detectable by tracking other stars trapped within their gravity wells, an idea Herschel used to discover binary stars. Tyson then describes the nature of black holes, their enormous gravitational forces that can even capture light, and their discovery via X-ray sources such as Cygnus X-1. Tyson uses the Ship of Imagination to provide a postulate of the warping of spacetime and time dilation as one enters the event horizon of the black hole, and the possibility that these may lead to other points within our universe or others, or even time travel. Tyson ends on noting that Herschel's son, John would be inspired by his father to continue to document the known stars as well as contributions towards photography that play on the same nature of deep time used by astronomers.

Lucy Worsley continues her journey through Russia in the footsteps of the Romanovs, the most powerful royal dynasty in modern European history. In this episode she examines the extraordinary reign of Catherine the Great, and the traumatic conflict with napoleonic France that provides the setting for the novel War and Peace. At the magnificent palace of Peterhof near St Petersburg, Lucy charts the meteoric rise of Catherine the Great, who seized the Russian throne from her husband Peter III in 1762 and became the most powerful woman in the world. Catherine was a woman of huge passions - for art, for her adopted country (she was German by birth) and for her many lovers.
Catherine expanded her empire through military victories overseas, while at home she encouraged education and introduced smallpox inoculation to Russia. But Catherine struggled to introduce deeper reforms, and the institution of serfdom remained largely unchanged. Lucy explains how this injustice fuelled a violent rebellion. Nevertheless, Catherine left Russia more powerful on the world stage than ever. But all she had achieved looked set to be undone when Napoleon invaded Russia in 1812. Lucy relives the pivotal battle of Borodino, when the Russian army finally confronted the French forces; the traumatic destruction of Moscow; and, under Catherine's grandson Alexander, the eventual victory over the French that provided the Romanov dynasty with its most glorious hour.

The Romanovs retreat into a bubble of luxury while the czar's forces brutally suppress protests by a starving populace. Rasputin's influence grows, never mind the rumors and scandals. Many people believe Prime minister Peter Stolypin is the last hope of the Romanov Dynasty as reformer-in-chief. He is horrified by the rise of Rasputin. The fight between Stolypin and Rasputin is a battle for influence over Nicholas II. But Stolypin is shot in the Kiev Opera in 1911.