There is a second cracking noise. Before this sound even reaches her ears, the rocket darts horizontally like a minnow, makes one or two minor cuts to correct its course, zeroes in on that sniper's perch, up in the water tower's access ladder. There is a great nasty explosion without any flame or light, like the loud pointless booms that you get sometimes at fireworks shows. For a moment, she can hear the clamor of shrapnel ringing through the ironwork of the water tower.

Just before she kicks her way back into the maze, a dustline whips past her, snapping rocks and fragments of broken glass into her face. It shoots into the maze. She hears it Ping-Pong all the way through, kicking off the steel walls in order to change direction. It's a Rat Thing clearing the way for her.

How sweet!

"Smooth move, Ex-Lax," she says, climbing back into Ng's van. Her throat feels thick and swollen. Maybe it's from screaming, maybe it's the toxic waste, maybe she's getting ready to gag. "Didn't you know about the snipers?" she says. If she can keep talking about the details of the job, maybe she can keep her mind off of what the Whirlwind Reaper did.

"I didn't know about the one on the water tower," Ng says. "But as soon as he fired a couple of rounds, we plotted the bullets' trajectories on millimeter-wave and back-traced them." He talks to his van and it pulls out of its hiding place, headed for I-405.

"Seems like kind of an obvious place to look for a sniper."

"He was in an unfortified position, exposed from all sides," Ng says. "He chose to work from a suicidal position. Which is not a typical behavior for drug dealers. Typically, they are more pragmatic. Now, do you have any other criticisms of my performance?"

"Well, did it work?"

"Yes. The tube was inserted into a sealed chamber inside the helicopter before it discharged its contents. It was then flash-frozen in liquid helium before it could chemically self-destruct. We now have a sample of Snow Crash, something that no one else has been able to get. It is the kind of success on which reputations such as mine are constructed."

"How about the Rat Things?"

"How about them?"

"Are they back in the van now? Back there?" Y.T. jerks her head aft.

Ng pauses for a moment. Y.T. reminds herself that he is sitting in his office in Vietnam in 1955 watching all of this on TV.

"Three of them are back," Ng says. "Three are on their way back. And three of them I left behind to carry out additional pacification measures."

"You're leaving them behind?"

"They'll catch up," Ng says. "On a straightaway, they can run at seven hundred miles per hour."

"Is it true they have nuke stuff inside of them?"

"Radiothermal isotopes."

"What happens if one gets busted open? Everyone gets all mutated?"

"If you ever find yourself in the presence of a destructive force powerful enough to decapsulate those isotopes," Ng says, "radiation sickness will be the least of your worries."

"Will they be able to find their way back to us?"

"Didn't you ever watch Lassie Come Home when you were a child?" he asks. "Or rather, more of a child than you are now?"

So. She was right. The Rat Things are made from dog parts.

"That's cruel," she says.

"This brand of sentimentalism is very predictable," Ng says.

"To take a dog out of his body - keep him in a hutch all the time."

"When the Rat Thing, as you call it, is in his hutch, do you know what he's doing?"

"Licking his electric nuts?"

"Chasing Frisbees through the surf. Forever. Eating steaks that grow on trees. Lying beside the fire in a hunting lodge. I haven't installed any testicle-licking simulations yet, but now that you have brought it up, I shall consider it."

"What about when he's out of the hutch, running around doing errands for you?"

"Can't you imagine how liberating it is for a pit bull-terrier to be capable of running seven hundred miles an hour?"

Y.T. doesn't answer. She is too busy trying to get her mind around this concept.

"Your mistake," Ng says, "is that you think that all mechanically assisted organisms - like me - are pathetic cripples. In fact, we are better than we were before."

"Where do you get the pit bulls from?"

"An incredible number of them are abandoned every day, in cities all over the place."

"You cut up pound puppies?"

"We save abandoned dogs from certain extinction and send them to what amounts to dog heaven."

"My friend Roadkill and I had a pit bull. Fido. We found it in an alley. Some asshole had shot it in the leg. We had a vet fix it up. We kept it in this empty apartment in Roadkill's building for a few months, played with it every day, brought it food. And then one day we came to play with Fido, and he was gone. Someone broke in and took him away. Probably sold him to a research lab."

"Probably," Ng says, "but that's no way to keep a dog."

"It's better than the way he was living before."

There's a break in the conversation as Ng occupies himself with talking to his van, maneuvering onto the Long Beach Freeway, headed back into town.

"Do they remember stuff?" Y.T. says.

"To the extent dogs can remember anything," Ng says. "We don't have any way of erasing memories."

"So maybe Fido is a Rat Thing somewhere, right now."

"I would hope so, for his sake," Ng says.

In a Mr. Lee's Greater Hong Kong franchise in Phoenix, Arizona, Ng Security Industries Semi-Autonomous Guard Unit B-782 comes awake.

The factory that put him together thinks of him as a robot named Number B-782. But he thinks of himself as a pit bull-terrier named Fido.

In the old days, Fido was a bad little doggie sometimes. But now, Fido lives in a nice little house in a nice little yard. Now he has become a nice little doggie. He likes to lie in his house and listen to the other nice doggies bark. Fido is part of a big pack.

Tonight there is a lot of barking from a place far away. When he listens to this barking, Fido knows that a whole pack of nice doggies is very excited about something. A lot of very bad men are trying to hurt a nice girl. This has made the doggies very angry and excited. In order to protect the nice girl, they are hurting some of the bad men.

Which is as it should be.

Fido does not come out of his house. When he first heard the barking, he became excited. He likes nice girls, and it makes him especially upset when bad men try to hurt them. Once there was a nice girl who loved him. That was before, when he lived in a scary place and he was always hungry and many people were bad to him. But the nice girl loved him and was good to him. Fido loves the nice girl very much.

But he can tell from the barking of the other doggies that the nice girl is safe now. So he goes back to sleep.

"'Scuse me, pod," Y.T. says, stepping into the Babel/Infocalypse room. "Jeez! This place looks like one of those things full of snow that you shake up."

"Hi, Y.T."

"Got some more intel for you, pod."

"Shoot."

"Snow Crash is a roid. Or else it's similar to a roid. Yeah, that's it. It goes into your cell walls, just like a roid. And then it does something to the nucleus of the cell."

"You were right," Hiro says to the Librarian, "just like herpes."

"This guy I was talking to said that it fucks with your actual DNA. I don't know what half of this shit means, but that's what he said."

"Who's this guy you were talking to?"

"Ng. Of Ng Security Industries. Don't bother talking to him, he won't give you any intel," she says dismissively.

"Why are you hanging out with a guy like Ng?"

"Mob job. The Mafia has a sample of the drug for the first time, thanks to me and my pal Ng. Until now, it always self-destructed before they could get to it. So I guess they're analyzing it or something. Trying to make an antidote, maybe."