Using vivid descriptions and a wealth of personal stories and anecdotes, this work tells of the origins, biology and destiny of such scourges of the human race as bubonic plague, malaria, typhoid, cholera, syphilis and AIDS. In this book for the general reader, Wills demonstrates the effect of these diseases on the entire evolutionary process - how they have done more to shape the teeming diversity of life on our planet than we realise. It draws on graphic evidence from places as remote from each other as the slums of Calcutta and the Peruvian rain forests to show how the evolution of plagues has also had an important role in shaping our own species, man. However, plagues are unusual events, and the cells which cause them have often gone out on an evolutionary limb, risking their own destruction. Wills's scientific insights demonstrate repeatedly how plague organisms can only overwhelm our defences by reducing their own, rendering themselves more vulnerable in the process.