NICHOLAS DAY is the author of Baby Meets World, a work of narrative nonfiction for adults about the science and history of infancy, which Mary Roach called "a perfect book." He has written regularly for Slate; his work has also appeared inthe Atlantic, the New York Times, and the Washington Post, among other publications. He lives in Western Massachusetts with his family. BRETT HELQUIST is the illustrator of classics such as A Series of Unfortunate Events by Lemony Snicket, The House of Bunnicula by James Howe, and books by Blue Balliet, including the New York Times bestselling Chasing Vermeer. Visit him on the Web at bretthelquist.com or on Instagram at @bhelquist.