Looking back on the book now, I like the reason the bad guy gives for setting the virus on the city. He says that in nature, natural events like disease and environmental crises are what keeps a species' population under control. They become too numerous, the food runs out, they all get diseased, and the population goes way down again. Balance is restored. But humans, because of our intelligence and technology, have nothing that keeps our population down. We've outsmarted the plagues that would otherwise keep our numbers in check. Now we're overpopulated in much of the earth, and destroying it in many other ways because of our numbers. So to the bad guy (Cope is his name), the solution was to set loose a disease that no one would be able to control, so the human population would be reduced, like how it was after the black plague. He pointed out that the end of the black plague led to tremendous prosperity for those who survived, and, in Cope's opinion, the end of the dark ages and birth of the Renaissance. Sadly, I kind of agree that it's sort of a problem that humans have no natural problems like that to keep us in place. But obviously, killing millions or even billions of people deliberately doesn't seem like the right solution. As horribly morbid as it is, I almost wish that some natural disease or crisis would come along and lower our numbers, with nobody at fault. That sounds evil though. Still, I see Cope's point. Sometimes I wonder if the massive destruction of our earth is going to be the thing that cuts us down, and that would really be a shame. Or maybe nuclear war will do it. Or maybe nothing will come along, and we'll just all die from lack of resources.

I finished the book, as much as I tried to take it nice and slow. It isn't really the kind of book you can take nice and slow. There are three sections throughout the book, called Invisible History I, II, and III. Preston pauses the action of the story to talk about events in the history of biological warfare and the development of biological weapons. Normally history lessons like this are pretty boring and I just want to get back to the story, but they actually were interesting and I learned SO much about bio weapons. Preston makes everything in his stories so realistic and accurate through all the research he does, so it kind of felt like half the time I was reading about something that was real. 

Through some witty forensics and a lot of digging, they track down the man who has been setting the virus (the Cobra virus) on the city. They connect the virus to Lesch-Nyhan disease, which is a terrible, rare genetic disease in boys that causes violence, self-cannibalism, and other nervous system problems. The last few scenes are really intense and suspenseful because the terrorist guy suspects that they've found him, and they don't want to rush in and grab him because he might set off a bunch of virus bombs. At the end he's beginning to show the effects of having contracted Cobra himself, which is scary because people go berserk and violent when they get it. Then there's a crazy chase between him and the two main characters all through the subway tunnels of Manhattan. It ends up being a lot like the climax of Silence of the Lambs.