The fourth episode sees host Neil deGrasse Tyson exploring our eternal quest to end hunger and honoring Nikolai Ivanovic Vavilov, pioneer of modern plant breeding, who risked his life for a discovery that would change the history of science. Vavilov's story is marked by both the tenacity and creativity and is particularly tragic. Interwoven into Vavilov's somber narrative are warnings and treatments of science and its ethical implications, especially when science itself comes under attack from political forces.

A child lies on the rug of a tenement dreaming of interstellar adventures. At the dawn of the space age, a young Carl Sagan’s career is forged in the clash of his mentors, two scientific titans. Sagan goes on realize his childhood dreams, to carry their research forward and communicate its significance to the whole world.

Episode 7 focuses specifically on first contact and the search for intelligent life in the vastness of the cosmos. Are humans ready to make first contact with other intelligent beings? Is our technology even sophisticated enough to detect communication signals from another world? Who are we to search for alien intelligence when we can't even recognize or respect the consciousness all around us, or even beneath our feet.
Neil deGrasse Tyson reveals the hidden underground network that is a collaboration of four kingdoms of life, and a true first contact story between humans and beings who communicate in a symbolic language and have maintained a representative democracy for many tens of millions of years.

A fifth of the land on our planet is covered by desert. Deserts may appear to be barren and empty, but they are of crucial importance to life. For those that can overcome their challenges they provide a vital refuge. The Grasslands are one of our planet's most productive landscapes. They support the greatest aggregations of large animals on Earth. Cameras follow desert elephants seeking sustenance, bison roaming North American grasslands and caterpillars living the good life underground.

Dave Grohl returns to his musical roots, while the Foo Fighters prepare to record at Seattle's Robert Lang Studio with Death Cab for Cutie's Benjamin Gibbard. Dave sets his focus on the Seattle music scene, mainly the grunge movement and its implications in American Rock Music. Interviews with Chris Cornell, Nancy Wilson, Bruce Pavitt.

The second part of this series begins with his return home after his discharge from the army, and how he dealt with a rapidly changing pop scene.
The picture is more complicated than even a fairly serious Elvis fan may understand. Priscilla Presley, who made some appearances in the first part, offers much more here, helping us understand how being forced into making a string of lousy movies was one kind of artistic prison, and then being ensconced in casino hotels for his famous Las Vegas residency was another. The man who had so carefully created his original persona was now stuck in the shallow roles others forced him to play.