NEAL STEPHENSON

329

___________ The virus that ate through Da5id’s brain was a string of binary information, shone into his face in the form of a bitmap-a series of white and black pixels, where white repre. sents zero and black represents one. They put the bitmap onto scrolls and gave the scrolls to avatars who went around the Metaverse looking for victims.

The Clint who tried to infect Hiro in The Black Sun got away, but he left his scroll behind-he didn’t reckon on having his arms lopped off-and Hiro dumped it into the tunnel system below the floor, the place where the Graveyard Daemons live. Later, Hiro had a Daemon take the scroll back to his workshop. And anything that is in Hiro’s house is, by definition, stored inside his own computer. He doesn’t have to jack into the global network in order to access it.

It’s not easy working with a piece of data that can kill you. But that’s okay. In Reality, people work with dangerous substances all the time-radioactive isotopes and toxic chemicals. You just have to have the right tools: remote manipulator arms, gloves, goggles, leaded glass. And in Flatland, when you need a tool, you just sit down and write it. So Hiro starts by writing a few simple programs that enable him to manipulate the contents of the scroll without ever seeing it.

The scrŕll, like any other visible thing in the Metaverse, is a piece of software. It contains some code that describes what it looks like, so that your computer wifi know how to draw it, and some routines that govern the way it rolls and unrolls. And it contains, somewhere inside of itself, a resource, a hunk of data, the digital version of the Snow Crash virus.

Once the virus has been extracted and isolated, it is easy enough for Hiro to write a new program called SnowScan. SnowScan is a piece of medicine. That is, it is code that protects Hiro’s system-both his hardware and, as Lagos would put it, his bioware-from the digital Snow Crash virus. Once Hiro has installed it in his system, it will constantly scan the information coming in from outside, looking for data that matches the contents of the scroll. If it notices such information, it will block it.

There’s other work to do in Flatland. Hiro’s good with avatars, so he writes himself an invisible avatar-just because, in the new