Providing a cover for our delicate and intricate bodies, the skin is our largest and fastest-growing organ. We see it, touch it, and live in it every day. It is a habitat for a mesmerizingly complex world of micro-organisms and physical functions that are vital to our health and our survival. It is also a waste removal plant, a warning system for underlying disease and a dynamic immune barrier to infection. One of the first things people see about us, skin is crucial to our sense of identity, providing us with social significance and psychological meaning. And yet our skin and the fascinating way it functions is largely unknown to us. In prose as lucid as his research underlying it is rigorous, blending in memorable stories from the past and from his own medical experience, Monty Lyman has written a revelatory book exploring our outer surface that will surprise and enlighten in equal measure. Through the lenses of science, sociology, and history--on topics as diverse as the mechanics and magic of touch (how much goes on in the simple act of taking keys out of a pocket and unlocking a door is astounding), the close connection between the skin and the gut, what happens instantly when one gets a paper cut, and how a midnight snack can lead to sunburn--Lyman leads us on a journey across our most underrated and unexplored organ and reveals how our skin is far stranger, more wondrous, and more complex than we have ever imagined.