As bird flu continues to spread around the world and the number of people dying from hospital-acquired infections rises yearly, the possibility of another plague has become a terrifying prospect. World leaders are now struggling against two critical foes. Firstly they need contingency plans that can cope with another pandemic. Secondly they need to combat global terrorism. And then there is the very real potential for an unprecedented and devastating combination of the two - biological warfare. This gripping study of biological agents of disease explores the history of outbreaks, points to the most insidious strains on the horizon, and explores the likelihood of deliberate contamination.