Dr. Frank Ryan takes us into the "hot zones" of today's most dangerous outbreaks, then into the research laboratories and hospitals, where he spotlights the scientists and doctors who are risking their lives to contain them. In telling this global story, he uncovers a frightening pattern - and concludes that new, deadlier diseases are even now waiting to emerge. Why do such plagues arise? Where do new viruses come from?

Could there be - will there be - a Virus X, an incurable virus, as lethal as Ebola, spread as easily as the common cold? Dr. Ryan has posed these questions to leading experts around the world, and here, combined with his own research as a renowned authority on diseases, he presents a radical theory about the origins of these deadly microbes.

Virus X asks provocative questions about human impact on an already delicate ecosystem and exposes our increasing vulnerability in a world out of balance. Yet in exploring the steps that can be taken to head off a potential doomsday, Virus X also provides a rousing call to action.