Today it was nowhere near toner war levels, but it was fairly intense. Judge Fang suspected that this had something to do with the purpose of this errand, which Miss Pao had declined to explain.

They ended up in a restaurant. Miss Pao insisted on a table out on the terrace, even though it looked like rain. They ended up overlooking the street three stories below. Even at that distance it was difficult to make out faces through the fog.

Miss Pao drew a rectangular package from her bag, wrapped up in Nanobar. She unwrapped it and drew out two objects of roughly the same size and shape: a book and a block of wood. She placed them side by side on the table. Then she ignored them, turning her attention to the menu. She continued to ignore them for several minutes more, as she and Chang and Judge Fang sipped tea, exchanged polite chatter, and began to eat their meals.

"At Your Honor's convenience," Miss Pao said, "I would invite you to examine the two objects I laid on the table."

Judge Fang was startled to notice that, while the block's appearance had not changed, the book had become covered in a layer of thick gray dust, as if it had been growing mildew for several decades.

"Oooh," Chang blurted, sucking a lengthy skein of noodles into his maw and bulging his eyes in the direction of this peculiar exhibit.

Judge Fang rose, walked around the table, and bent down for a closer look. The gray dust was not uniformly distributed; it was much thicker toward the edges of the book cover. He opened the book and was startled to notice that the dust had infiltrated deep between the pages.

"This is dust with a purpose in life," Judge Fang observed. Miss Pao glanced significantly at the block of wood. Judge Fang picked it up and examined it on all sides; it was clean. "This stuff is discriminating too!" Judge Fang said.

"It is Confucian toner," Chang said, finally choking down his noodles. "It has a passion for books."

The Judge smiled tolerantly and looked to Miss Pao for an explanation. "You have examined this new species of mite, I take it?"

"It is more interesting than that," Miss Pao said. "Within the last week, not one but two new species of mite have appeared in the Leased Territories– both programmed to seek out anything that looks like a book." She reached into her bag again and handed her master a rolled-up piece of mediatronic paper.

A waitress scurried up and helped move the dishes and teacups aside. Judge Fang unrolled the page and anchored it with various small items of faience. The paper was divided into two panes, each containing a magnified view of a microscopic device. Judge Fang could see that both were made to navigate through the air, but beyond that, they could hardly have been more different. One of them looked like a work of nature; it had several bizarre and elaborate arms and sported four enormous, wildly involuted, scooplike devices, arranged ninety degrees apart.

"The ears of a bat!" Chang exclaimed, tracing their impossibly complex whorls with the tip of a chopstick. Judge Fang said nothing but reminded himself that this sort of quick insight was just the sort of thing Chang excelled at.

"It appears to use echolocation, like a bat," Miss Pao admitted. "The other one, as you can see, is of a radically different design." The other mite looked like a spacecraft as envisioned by Jules Verne. It had a streamlined, teardrop shape, a pair of manipulator arms folded neatly against its fuselage, and a deep cylindrical cavity in the nose that Eudge Fang took to be its eye.

"This one sees light in the ultraviolet range," Miss Pao said. "Despite their differences, each does the same thing: searches for books. When it finds a book, it lands on the cover and :rawls to the edge, then creeps between the pages and examines the internal structure of the paper."

"What is it looking for?"

"There is no way to tell, short of disassembling its internal computer system and decompiling its program– which is difficult," Miss Pao said, with characteristic understatement. "When it finds that it has been investigating a normal book made of old-fashioned paper, it deactivates and becomes dust."

"So there are many dirty books in the Leased Territories now," Chang said.

"There aren't that many books to begin with," Judge Fang said. Miss Pao and Chang chuckled, but the Judge showed no sign that he had been making a joke; it was just an observation. "What conclusions do you draw, Miss Pao?" the Judge said.

"Two different parties are searching the Leased Territories for the same book," Miss Pao said. She did not have to state that the target of this search was probably the book stolen from the gentleman named Hackworth.

"Can you speculate as to the identity of these parties?"

Miss Pao said, "Of course, neither device carries a maker's mark. The bat-eared one has Dr. X written all over it; most of its features appear to be evolved, not engineered, and the Doctor's Flea Circus is nothing more than an effort to collect evolved mites with useful features. At a first glance, the other device could have come from any of the engineering works associated with major phyles– Nippon, New Atlantis, Hindustan, the First Distributed Republic being prime suspects. But on deeper examination I find a level of elegance-"

"Elegance?"

"Pardon me, Your Honor, the concept is not easy to explain– there is an ineffable quality to some technology, described by its creators as concinnitous, or technically sweet, or a nice hack– signs that it was made with great care by one who was not merely motivated but inspired. It is the difference between an engineer and a hacker."

"Or an engineer and an artifex?" Judge Fang said.

A trace of a smile came across Miss Pao's face. "I fear that I have enmeshed that little girl in a much deeper business than I ever imagined," Judge Fang said. He rolled up the paper and handed it back to Miss Pao. Chang set the Judge's teacup back in front oi him and poured more tea. Without thinking about it, the Judge put his thumb and fingertips together and tapped them lightly against the tabletop several times. This was an ancient gesture in China. The story was that one of the early Emperors liked to dress as a commoner and travel about the Middle Kingdom to see how the peasants were getting along. Frequently, as he and his staff were sitting about the table in some inn, he would pour tea for everyone. They could not kowtow to their lord without giving away his identity, so they would make this gesture, using their hand to imitate the act of kneeling. Now Chinese people used it to thank each other at the dinner table. From time to time, Judge Fang caught himself doing it: and thought about what a peculiar thing it was to be Chinese in a world without an Emperor.

He sat, hands folded into sleeves, and thought about this and other issues for several minutes, watching the vapor rise from his tea and forn into a fog as it condensed round the bodies of micro-aerostats.

"Soon we will obtrude upon Mr. Hackworth and Dr. X and learn more by observing their reactions. I will consider the right way to sei about this. In the meantime, let us concern ourselves with the girl. Chang, visit her apartment building and see whether there has been any trouble there– suspicious characters hanging about."

"Sir, with all respect, everyone who lives in the girl's building is of suspicious character."

"You know what I mean," said the Judge with some asperity. "The building should have a system for filtering nanosites from the air. If this system is working properly, and if the girl does not take the book out of her building, then she should go unnoticed by these." The Judge drew a streak through the dust on the book's cover and smeared the toner between his fingers. "Speak with the landlord of her building, and let him know that his air-filtering system is due for an inspection, and that this is genuine, not just a solicitation for a bribe."