Here is a compelling scientific account of viruses, their history, and the dangers they pose--now and in the future. Viruses are disarmingly small and simple. Nevertheless, the smallpox virus killed over 300 million people in the twentieth century before it was eradicated in 1980. The AIDS virus, HIV, is now the world's biggest killer infection and the single most common cause of death in Africa. In recent years, the outbreaks of several lethal viruses...