Viruses are the tiniest creatures known to science, yet our entire planet is under their control. Every person is well aware of cold and flu viruses, but there are also viruses that can cause the most bizarre diseases, such as when tree-like growths develop on a person’s skin. Viruses are not just part of our lives: the human genome contains more of their genetic material than our own genes. Meanwhile, scientists continue to discover viruses everywhere: in the soil, in the ocean, even in caves thousands of meters deep. This amazing book introduces us to the secret world in which we all live. Drawing on the latest research, popular science journalist Carl Zimmer reveals how viruses control our lives and the biosphere, how they gave impetus to the development of the first forms of life on earth, and how they will determine our destinies in the future.