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.

A Chapter of forgotten history. The first permanent European settlement in the United States was founded in 1565–two generations before the settlements in Jamestown and Plymouth–not by English Protestants, but by the Spanish and a melting pot of people they brought with them from Africa, Italy, Germany, Ireland and even converted Jews, who integrated almost immediately with the indigenous tribes.
The film uncovers one story of America’s past that never made it into textbooks. Follow some of America’s leading archaeologists, maritime scientists, and historians as they share the story of Florida’s earliest settlers. It’s a story that has taken more than 450 years to reveal.

Laurent Ballesta has yet again challenged himself to a new world record: spend 28 days at a depth of 100 meters to reveal the luxuriant and unknown depths of the Mediterranean.
Because people have been travelling there for thousands of years, this sea is be­lieved to be without secrets. And yet, far below its surface, lie vast unexplored territories, luxurious gardens worthy of the finest tro­pical coral reefs. These natural wonders are inaccessible to the traditional diver, in a twilight zone, between 60 and 120 m, where there’s less than 1% of sunlight. If diving at such depths is always a challenge, staying there is a fan­tasy, a utopia that becomes reality in 'The Deep Med'.

Putin thinks that the West must understand that today's Russia cannot function exactly as the West does, already. Putin also explains his views on NATO, and cannot see any reason to why this military alliance has grown after the fall of Communism in Europe.
When Stone asks about Putin's views on Edward Snowden and whether he is a traitor or not, Putin replies, 'No he is not, as he never has worked for any foreign country,' and also claims that Russian intelligence does not know anything more than what Snowden already had leaked before he arrived at Moscow.

The final episode of the series ponders the fate of planet Earth. Neil deGrasse Tyson opens with a reflection on science and those who help us understand it: 'We all feel the weight of the shadows on our future, but in another time, every bit as ominous as our own, there were those who could see a way through the darkness to find a star to steer by.'
The young Carl Sagan and Neil Tyson first discovered their passion for science at the NY World's Fairs of the past. We visit the dazzling Pavilions of the 2039 NY World's Fair, where problems we currently think intractable have been plausibly solved through public commitment and scientific imagination. And our baby is a woman now, with a baby of her own and a future bright with possibilities.

Bitcoin is a peer-to-peer monetary system in which all transaction records are public. Participants can use its open-source software to transfer virtual currency to one another as easily as they might send an email. Bitcoin opens an uncharted world of new possibilities to explore. We'll follow the stories of entrepreneurs and startups that are helping shape the new financial frontier. We'll look at the competitive mining market and the various subcultures within the Bitcoin community." You'll encounter a variety of characters and opinions as we examine the social and political impact of an open-source digital currency. Will the rise of Bitcoin bring a monetary paradigm shift that will forever change the world? Supposedly invented by a mysterious Japanese man named Satoshi Nakamoto (whose current whereabouts are unknown). Because it is designed to have an absolute ceiling of 21 million Bitcoins in circulation (not anticipated until 2040), and the system has no central depository or administrative authority, it has great appeal to libertarians and others who seek alternatives to a perceived corrupt, manipulative banking infrastructure and excessive government regulations. Its low processing fees compared with those of mainstream credit-card companies also hold considerable allure for merchants.