This fast-paced and exciting book tells the fictional story of the outbreak of a deadly new virus and the havoc it wreaks in its wake. The story begins mysteriously in New Mexico some nine years in the past and then shifts to the present time to the rain forests of Sumatra. There, a brilliant American botanist named Jonathan Rhodes is searching and classifying Sumatran plant life in the hopes of discovering new medicinal plants, thus single-handedly ensuring the survival of the rain forest. He has brought his twelve-year-old twin daughters (on their summer break from school) with him on this excursion so they can experience real-life science lessons. Also accompanying him is his much-younger female love interest, who is also a botanist. Rhodes's ex-wife, Holly, decides that she misses her daughters too much, and after they've been gone for two weeks, she decides to fly out to Sumatra to visit them. She has never gotten over her love for her ex-husband and secretly hopes that maybe this reunion of sorts will serve to re-unite them. In the meantime, a deadly virus has broken out in the Sumatran rain forests where Rhodes's camp is, beginning with an animal hunter named Ahmad, who specializes in capturing monkeys to sell, and spreading to thousands of others across the country, killing each and every one of its victims. The disease shows up in an animal holding facility in the U.S., where monkeys for experimental use have just been imported from Sumatra. A U.S. military virological team of experts is sent to Sumatra, after several U.S. scientists die, in the hopes of discovering the vector. The leader of the team is a strong and admirable woman character named Lieutenant Colonel Carmen Travis.
The fatal course of the disease is described in gruesome detail and effectively serves to scare the reader into begging for answers and into trying his hand at an explanation into the origin of the virus. The book briefly explores the sordid world of prostitution and the selling of pre-pubescent girls in third-world societies. It also touches upon the antipathy of the Muslim world towards the United States. Ironically, their worst fears and beliefs are realized in the incredible conclusion of this book.