Overview: As Bill breaks down the science of aging, his correspondents try bizarre beauty treatments and learn how spinach could transform organ transplants.
Overview: Derek Muller discovers why Mexico City is sinking, Nazeem Hussain tests his desert survival skills, and Bill has a drink with a "water sommelier".
Overview: Bill explains how addiction changes the brain, comedian Maria Bamford shares her struggles, and Cara Santa Maria visits a research lab casino.
Overview: Karlie Kloss tours Japanese farms that grow produce without soil to save water and space. Back in the studio, Margaret Cho samples meat made in a lab.
Overview: In London, mutated mosquitos make a meal of Derek Muller. Comedian Paul F. Tompkins helps Bill burst a common myth about evolution.
Overview: Do dogs get depressed? Do monkeys like magic tricks? Bill and his guests explore animal behavior that's remarkably human