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.

In 1799, the German scientist Alexander von Humboldt embarked on a perilous journey of discovery across South America. It would take him to the deepest jungle near the Orinoco and to the heights of the Andes. His aim was twofold: to conduct the first scientific survey of South America and to discover how the natural world actually works — at a time when most scientists believed that the world was created less than 6,000 years ago. He later became a leading scientific figure and champion of the abolitionist movement in the US.
This extremely visual docudrama follows Humboldt’s extraordinary path. Travelling in Humboldt’s footsteps is historian Andrea Wulf, whose book on Humboldt became a worldwide bestseller. For good reason, since Humboldt’s ideas on the planet’s fragile web of life are as important today as they were 220 years ago.

Visit the ghostly villages surrounding Chernobyl (abandoned by humans after the 1986 nuclear disaster), travel to remote islands off the coast of Maine to search for abandoned towns that have vanished from view in only a few decades, then head beneath the streets of New York to see how subway tunnels may become watery canals. A visual journey, LIFE AFTER PEOPLE is a thought provoking adventure that combines movie-quality visual effects with insights from experts in the fields of engineering, botany, ecology, biology, geology, climatology, and archaeology to demonstrate how the very landscape of our planet will change in our absence.