ns climbing the steps into his private jet. It's daytime. A wall of billowing orange flame grows up silently from the tank farm a mile away, like a time-lapse chrysanthemum. It is so vast and complicated in its blooming, uncontrolled growth that Rife stops halfway up the stairs to watch. A powerful disturbance is moving through the flame, leaving a linear trail in the light, like a cosmic ray fired through a cloud chamber. By the force of its passage, it leaves behind a shock wave that is clearly visible in the flame, a bright spreading cone that is a hundred times larger than the dark source at its apex: a black bulletlike thing supported on four legs that are churning too fast to be visible. It is so small and so fast that L. Bob Rife would not be able to see it, if it were not headed directly for him. It is picking its way over a broad tangle of open-air plumbing, the pipes that carry the fuel to the jets, jumping over some obstacles, digging its metallic claws into others, tearing them open with the explosive thrust of its legs, igniting their contents with the sparks that fly whenever its feet touch the pavement. It gathers its four legs under it, leaps a hundred feet to the top of a buried tank, uses that as a launch pad for another long, arcing leap over the chain link fence that separates the fuel installation from the airport proper, and then it settles into a long, steady, powerful lope, accelerating across the perfect geometric plane of the runway, chased by a long tongue of flame that extends lazily from the middle of the conflagration, whorling inward upon itself as it traces the currents in that Rat Thing's aftershock. Something tells L. Bob Rife to get away from the jet, which is loaded with fuel. He turns and half jumps, half falls off the stairs, moving clumsily because he's looking at the Rat Thing, not at the ground. The Rat Thing, just a tiny dark thing close to the ground, visible only by virtue of its shadow against the flames, and by the chain of white sparks where its claws dig into the pavement, makes a tiny correction in its course. It's not headed for the jet; it's headed for him. Rife changes his mind and runs up the stairway, taking the steps three at a time. The stairway flexes and recoils under his weight, reminding him of the jet's fragility. The pilot has seen it coming, doesn't wait to retract the stairway before he releases the brakes and sends the jet taxiing down the runway, swinging the nose away from the Rat Thing. He punches the throttles, nearly throwing the jet onto one wing as it whips around in a tight curve, and redlines the engines as soon as he sees the center line of the runway. Now they can only see forward and sideways. They can't see what is chasing them. Y.T. is the only person who can see it happen. Having easily penetrated airport security with her Kourier pass, she is coasting onto the apron near the cargo terminal. From here, she has an excellent view across half a mile of open runway, and she sees it all happen: the plane roars down the runway, hauling its door closed as it goes, shooting pale blue flames out its engine nozzles, trying to build up speed for takeoff, and Fido chases it down like a dog going after a fat mailman, makes one final tremendous leap into the air and, turning himself into a Sidewinder missile, flies nose-first into the tailpipe of its left engine. The jet explodes about ten feet off the ground, catching Fido and L. Bob Rife and his virus all together in its fine, sterilizing flame. How sweet! She stays for a while and watches the aftermath: Mafia choppers coming in, doctors jumping out with doc boxes and blood bags and stretchers, Mafia soldiers scurrying between the private jets, apparently looking for someone. A pizza delivery car takes off from one of the parking areas, tires squealing, and a Mafia car peels out after it in hot pursuit. But after a while it gets boring, and so she skates back to the main terminal, under her own power mostly, though she manages to poon a fuel tanker for a while. Mom's waiting for her in her stupid little jellybean car, by the United baggage claim, just like they arranged on the phone. Y.T. opens the door, throws her plank into the back seat, and climbs in. "Home?" Mom says. "Yeah, home seems about right." ACKNOWLEDGEMENTS This book germinated in a collaboration between me and the artist Tony Sheeder, the original goal of which was to publish a computer-generated graphic novel. In general, I handled the words and he handled the pictures; but even though this work consists almost entirely of words, certain aspects of it stem from my discussions with Tony. This novel was very difficult to write, and I received a great deal of good advice from my agents Liz Darhansoff, Chuck Verrill, and Denise Stewart, who read early drafts. Other people subjected to the early drafts were Tony Sheeder; Dr. Steve Horst of Wesleyan University, who made extensive and very lucid comments on everything having to do with brains and computers (and who suddenly came down with a virus about one hour after reading it); and my brother-in-law, Steve Wiggins, currently at the University of Edinburgh, who got me started on Asherah to begin with and also fed me useful papers and citations as I thrashed around pitifully in the Library of Congress. Marco Kaltofen, as usual, functioned in the same quick, encyclopedic way as the Librarian when I had questions about certain whys and wheres of the toxic-waste business. Richard Green, my agent in L.A., gave me some help with the geography of that town. Bruck Pollock read the galleys attentively, but with blistering speed, and made several useful suggestions. He was the first and certainly not the last to point out that BIOS actually stands for "Basic Input/Output System," not "Built-In Operating System" as I have it here (and as it ought to be); but I feel that I am entitled to trample all other considerations into the dirt in my pursuit of a satisfying pun, so this part of the book is unchanged. The idea of a "virtual reality" such as the Metaverse is by now widespread in the computer-graphics community and is being implemented in a number of different ways. The particular vision of the Metaverse as expressed in this novel originated from idle discussion between me and Jaime (Captain Bandwidth) Taaffe - which does not imply that blame for any of the unrealistic or tawdry aspects of the Metaverse should be placed on anyone but me. The words "avatar" (in the sense used here) and "Metaverse" are my inventions, which I came up with when I decided that existing words (such as "virtual reality") were simply too awkward to use. In thinking about how the Metaverse might be constructed, I was influenced by the Apple Human Interface Guidelines, which is a book that explains the philosophy behind the Macintosh. Again, this point is made only to acknowledge the beneficial influence of the people who compiled said document, not to link these poor innocents with its results. In a nice twist, which I include only because it is pleasingly self-referential, I became intimately familiar with the inner workings of the Macintosh during the early phases of the doomed and maniacal graphic-novel project when it became clear that the only way to make the Mac do the things we needed was to write a lot of custom image-processing software. I have probably spent more hours coding during the production of this work than I did actually writing it, even though it eventually turned away from the original graphic concept, rendering most of that work useless from a practical viewpoint. It should be pointed out that when I wrote the Babel material, I was standing on the shoulders of many, many historians and archaeologists who actually did the research; most of the words spoken by the Librarian originated with these people and I have tried to make the Librarian give credit where due, verbally footnoting his comments like a good scholar, which I am not. Finally, after the first publication of Snow Crash I learned that the term "avatar" has actually been in use for a number of years as part of a virtual reality system called Habitat, developed by F. Randall Farmer and Chip Morningstar. The system runs on Commodore 64 computers, and though it has all but died out in the U.S., is still popular in Japan. In addition to avatars, Habitat includes many of the basic features of the Metaverse as described in this book. ABOUT THE AUTHOR NEAL STEPHENSON issues from a clan of rootless, itinerant hard-science and engineering professors (mostly Pac 10, Big 10, and Big 8 with the occasional wild strain of Ivy). He began his higher education as a physics major, then switched to geography when it appeared that this would enable him to scam more free time on his university's mainframe computer. When he graduated and discovered, to his perplexity, that there were no jobs for inexperienced physicist-geographers, he began to look into alternative pursuits such as working on cars, unimaginably stupid agricultural labor, and writing novels. His first novel, The Big U, was published in 1984 and vanished without a trace. His second novel, Zodiac: the Eco-thriller, came out in 1988 and quickly developed a cult following among water-pollution-control engineers. It was also enjoyed, though rarely bought, by many radical environmentalists. Snow Crash was written in the years 1988 through 1991 as the author listened to a great deal of loud, relentless, depressing music. The Diamond Age was his fourth novel and The Cobweb was his last. Mr. Stephenson now resides in a comfortable home in the western hemisphere and spends all of his time trying to retrofit an office into its generally dark, unlevel, and asbestos-laden basement so that he can attempt to write more novels. Despite the tremendous amounts of time he devotes to writing, playing with computers, listening to speed metal, Rollerblading, and pounding nails, he is a flawless husband, parent, neighbor, and all-around human being.