Dear Readers,   The events depicted in The End of October were meant to serve as a cautionary tale. But real life doesn't always wait for warnings. As I write, the entire world is enveloped in a viral disease much like the one I imagined within these pages.    It's been said that the book is a kind of prophecy, but I see it simply as the result of careful research. I asked the question: what is the gravest threat to human civilization? Nuclear war and global warming are existential threats, but throughout history diseases have periodically capsized societies. A century has passed since the 1918 "Spanish" flu that killed between fifty and a hundred million people. What if something like that returned, in our time, where travel is rapid and cities are densely populated and public health has receded as a primary concern?   I have applied the same rigorous standards that I bring to my nonfiction. Nothing presented here as factual is invented. I interviewed many scientists and epidemiologists who are now at the forefront of America's effort to constrain the pandemic. As for the geopolitics I describe, I merely extended trends I observed in the world to certain logical conclusions. I spoke to top government officials and military figures. Everyone I spoke to shared the concerns I expressed herein--something like this  could  happen. And now it has.   Of course, this book is a novel. One with heroes and villains and a clock ticking in the background. It was exciting to research and to write, and what I learned gave me hope about our institutions and the people who are working to shield us from catastrophe. I was particularly impressed by the ingenuity and courage of the people who have dedicated their lives to public health. It is to them that the novel is dedicated.   I hope you enjoy it.   Lawrence Wright Excerpted from The End of October: A Novel by Lawrence Wright All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.