Kyle Harper offers a history of infectious disease from a germ's perspective, showing how pathogens have shaped human civilization at every stage. Harper, a historian who previously examined disease in the Roman Empire, traces how our disease pool is rooted in evolution and accelerated by technology. The domestication of animals gave us new pathogens; cities concentrated them; global trade spread them. Harper examines the demographic catastrophes that followed: the Plague of Athens, the Black Death, the devastation of Indigenous Americans by Old World diseases. But he also shows how human societies have fought back through quarantine, public health, and eventually vaccines and antibiotics. The book connects biology, history, and ecology to show how humanity's relationship with the microbial world has been a central force in our development. Harper writes accessibly about complex scientific and historical material. For readers seeking to understand the pandemic in historical perspective, this book reveals how thoroughly disease has shaped human life and how remarkable our recent escape from that burden has been.