Will, a man scared of spiders his whole life, ventures deep into the Ecuadorian Amazon on an expedition in search of deadly creatures. Joined by professor Bryan Fry and local mountaineer Carla Perez, they abseil 200 feet into a cave network known as the "womb of the Earth," where they discover a giant tarantula. Using cutting-edge techniques, they extract its venom, which could hold the key to saving millions of lives.

Will travels to the kingdom of Bhutan on a deeply intimate journey in search of the secret to happiness. Guided by happiness expert professor Dacher Keltner and local writer Tshering Denkar, Will treks to one of the highest and happiest villages in the Himalayas, at 13,000-foot altitude. While there, he confronts some of the most challenging moments of his extraordinary life and career.