When a satellite, that has been sent into orbit to collect organisms that will be studied for signs of life, returns to Earth, its contents escape and, within a matter of minutes, kill all but two of the inhabitants of a small town in Arizona. The Wildfire Team, a collection of scientists that are brought together on a moment's notice, must try to identify what this bacterial strain is and how to stop it before it spreads across the nation and, eventually, the globe, killing everyone and everything in its path. The key to this solution lies in the two survivors of the bacteria's initial rampage - an 81-year-old man and a newborn baby. This book is very scientific in scope and can be quite confusing to any reader who has little to no science background even though Crichton does try to put it in layman-ese. The real tense moments in the book don't really start until the final 20 pages which results in some severe tedium for the opening 250 or so pages.