Mucus is an ambiguous thing. Slime is both disgusting and delicious. Mucus is both a vehicle for pathogens and the strongest weapon of our immune system. Mucus is the substance by which our world moves. Mucus exists at the junction of everything: between different organs and layers of our bodies, and between the earth, water and air in the environment. In the natural world, it often becomes a decisive argument in the fatal battle between predator and prey, and also plays a key role in the curious mating practices of underwater gastropods. In this astonishing book, Suzanne Wedlich gives a tour of a three-billion-dollar history of slime: from the role it played in the evolution of life on this planet to how it might manifest itself in the post-human life of the future. Wedlich explores the cultural and emotional significance of slime, from her special role in horror films to her subtle influence on art nouveau style. Slime is what unites Patricia Highsmith's love of snails, John Steinbeck's aversion to mixins and Emperor Hirohito's passion for jellyfish.