Professor Jim Al-Khalili investigates one of the most important concepts in the world today - information. He discovers how we harnessed the power of symbols, everything from the first alphabet to the electric telegraph through to the modern digital age. But on this journey he learns that information isn't just about human communication, it's woven very profoundly into the fabric of reality.

The Internet enables us to connect with people, images and information in ways that were unimaginable 30 years ago. But with every click we are re-wiring the physical structure of our brains. Are we evolving or actively de-evolving down a dopamine-laced click-hole? In this episode meet a 17-year-old boy struggling with an addiction to online pornography; autistic technologists in Silicon Valley who are turning their genetic variation to an advantage; plus, Nootropics, a class of cognition-enhancing supplements that claims to rewire the brain.

Beginning with the origins of the universe in the Big Bang, Sagan describes the formation of different types of galaxies and anomalies such as galactic collisions and quasars. The episodes moves further into ideas about the structure of the Universe, such as different dimensions (in the imaginary Flatland and four-dimensional hypercubes), an infinite vs. a finite universe, and the idea of an oscillating Universe (similar to that in Hindu cosmology). The search into other ideas such as dark matter and the multiverse is shown, using tools such as the Very Large Array in New Mexico. Cosmos Update shows new information about the odd, irregular surfaces of galaxies and the Milky Way perhaps being a barred spiral galaxy

Questions are raised about the search for intelligent life beyond the Earth, with UFOs and other close encounters refuted in favor of communications through SETI and radio telescope such as the Arecibo Observatory. The probability of technically advanced civilizations existing elsewhere in the Milky Way is interpreted using the Drake equation and a future hypothetical Encyclopedia Galactica is discussed as a repository of information about other worlds in the galaxy. The Cosmos Update notes that there have been fewer sightings of UFOs and more stories of abductions, while mentioning the META scanning the skies for signals.

Sagan discusses comets and asteroids as planetary impactors, giving recent examples of the Tunguska event and a lunar impact described by Canterbury monks in 1178. It moves to a description of the environment of Venus, from the previous fantastic theories of people such as Immanuel Velikovsky to the information gained by the Venera landers and its implications for Earth's greenhouse effect. The Cosmos Update highlights the connection to global warming.

In a world where nothing seems to ever work out as you had hoped, The Rehearsal features Nathan Fielder helping ordinary people rehearse difficult conversations or life events through the use of sets and actors hired to recreate real situations. The situations can be trivial, like confessing to a lie about educational history, or more complex, like raising a child. Fielder commissions extravagant sets with every detail recreated. He hires actors to inhabit these sets and practice different dialogue trees with his clients dozens of times. Information used to train the actors and build the sets is often collected without the subjects' knowledge.
In the firs episode, Nathan Fielder helps Kor Skeete, a Brooklyn-based trivia aficionado who wants to confess to his bar trivia team that he lied about having a master's degree. Nathan reveals an elaborate method of rehearsals involving an actor (K. Todd Freeman) playing a 'fake Kor'. To help Kor rehearse the difficult conversation with his teammate Tricia to clean this long-held lie, Nathan creates simulations of trivia night with a fake Tricia in a full-scale replica of the Alligator Lounge, a Brooklyn bar. Kor overcomes his fears and makes his confession to the real Tricia.