Epidemics are the scourges of mankind. The plague depopulated entire regions, cholera epidemics claimed millions of lives into the 20th century, HIV, a completely new and initially uncontrollable disease, emerged in the 1980s, and today Ebola, Sars, and avian flu are scaring us.Where do the pathogens of these epidemics come from, and why do some of them lead to epidemics? But above all, what can medicine and research do to counteract them? Kai Kupferschmidt tells the long, partly crime story of a multifaceted phenomenon whose end - one suspects - is not foreseeable.