Diamond Age

She was heartened by her success. But Castle Turing was only one of seven ducal seats in this kingdom, and she knew she had much work to do.

The territory around the castle was deeply forested, but grassy ridges rose several miles away, and standing on the castle walls with the original Duke's spyglass, Nell was able to see wild horses grazing there. Purple had taught her the secrets of mastering wild horses, and Duck had taught her how to win their affection, and so Nell mounted an expedition to these grasslands and returned a week later with two beautiful mustangs, Coffee and Cream. She equipped them with fine tack from the Duke's stables, marked with the T crest-for the crest was hers now, and she could with justification call herself the Duchess of Turing. She also brought a plain, unmarked saddle so that she could pass for a commoner if need be-though Princess Nell had become so beautiful over the years and had developed such a fine bearing that few people would mistake her for a commoner now, even if she were dressed in rags and walking barefoot.

Lying in her bunkbed in Madame Ping's dormitory, reading these words from a softly glowing page in the middle of the night, Nell wondered at that. Princesses were not genetically different from commoners.

On the other side of a fairly thin wall she could hear water ru

She stayed up late reading the Primer in the dark. The dormitory was a good place for this; Madame Ping's girls were professionals, and after a few minutes of whispering, giggling, and scandalized communal shushing, they always went to sleep.

Nell sensed that she was coming close to the end of the Primer. This would have been evident even if she hadn't been closing in on Coyote, the twelfth and final Faery King. In the last few weeks, since Nell had entered the domain of King Coyote, the character of the Primer had changed. Formerly, her Night Friends or other characters had acted with minds of their own, even if Nell just went along passively. Reading the Primer had always meant racting with other characters in the book while also having to think her way through various interesting situations.

Recently the former element had been almost absent. Castle Turing had been a fair sample of King Coyote's domain: a place with few human beings, albeit filled with fascinating places and situations.

She made her lonesome way across the domain of King Coyote, visiting one castle after another, and encountering a different conundrum in each one. The second castle (after Castle Turing) was built on the slope of a mountain and had an elaborate irrigation system in which water from a bubbling spring was routed through a system of gates. There were many thousands of these gates, and they were co

Once she understood that the behavior of the water-gates was orderly and predictable, it was not long before she was able to program their behavior and locate the bugs that the dark knight had introduced into the system. Soon water was flowing through the irrigation system again, and the famine was relieved.

The people who lived in this castle were grateful, which she had expected. But then they put a crown on her head and made her their ruler, which she had not expected.

On some reflection, though, it only made sense. They would die unless their system functioned properly. Princess Nell was the only person who knew how it worked; she held their fate in her hands. They had little choice but to submit to her rule.

So it went, as Princess Nell proceeded from castle to castle, inadvertently finding herself at the helm of a full-fledged rebellion against King Coyote. Each castle depended on some kind of a programmable system that was a little more complicated than the previous one. After the Castle of the Water-gates, she came to a castle with a magnificent organ, powered by air pressure and controlled by a bewildering grid of push-rods, which could play music stored on a roll of paper tape with holes punched through it.

A mysterious dark knight had programmed the organ to play a sad, depressing tune, plunging the place into a profound depression so that no one worked or even got out of bed. With some playing around, Princess Nell established that the behavior of the organ could be simulated by an extremely sophisticated arrangement of water-gates, which meant, in turn, that it could just as well be reduced to an unfathomably long and complicated Turing machine program.

When she had the organ working properly and the residents cheered up, she moved on to a castle that functioned according to rules written in a great book, in a peculiar language. Some pages of the book had been ripped out by the mysterious dark knight, and Princess Nell had to reconstruct them, learning the language, which was extremely pithy and made heavy use of parentheses. Along the way, she proved what was a foregone conclusion, namely, that the system for processing this language was essentially a more complex version of the mechanical organ, hence a Turing machine in essence.

Next was a castle divided into many small rooms, with a system for passing messages between rooms through a pneumatic tube. In each room was a group of people who responded to the messages by following certain rules laid out in books, which usually entailed sending more messages to other rooms. After familiarizing herself with some of these rule-books and establishing that the castle was another Turing machine, Princess Nell fixed a problem in the message-delivery system that had been created by the vexatious dark knight, collected another ducal coronet, and moved on to castle number six.

This place was entirely different. It was much bigger. It was much richer. And unlike all of the other castles in the domain of King Coyote, it worked. As she approached the castle, she learned to keep her horse to the edge of the road, for messengers were constantly blowing past her at a full gallop in both directions.

It was a vast open marketplace with thousands of stalls, filled with carts and ru

In the midst of this hubbub, Princess Nell saw a dark knight sitting on a black horse, paging through one of these books. Without further ado, she spurred her horse forward and drew her sword. She slew him in single combat, right there in the middle of the marketplace, and the book-sellers simply backed out of their way and ignored them as Princess Nell and the dark knight hacked and slashed at each other. When the dark knight fell dead and Princess Nell sheathed her sword, the commotion closed in about her again, like the waters of a turbulent river closing over a falling stone. Nell picked up the book that the dark knight had been reading and found that it contained nothing but gibberish. It was written in some kind of a cipher.

She spent some time reco

This castle proved fiendishly difficult to figure out, and Nell spent a few weeks working on it. Part of the problem was that this was the first castle Princess Nell had visited that was actually functioning as intended; the dark knight had not been able to foul the place up, probably because everything was done in ciphers here, and everything was decentralized. Nell discovered that a smoothly functioning system was much harder to puzzle out than one that was broken.

In the end, Princess Nell had to apprentice herself to a master cipherer and learn everything there was to know about codes and the keys that unlocked them. This done, she was given her own key, as a badge of her office, and found a job in one of the stalls enciphering and deciphering books. As it turned out, the key was more than just a decoration; rolled up inside its shaft was a strip of parchment inscribed with a long number that could be used to decipher a message, if the sender wanted you to decipher it. From time to time she would go to the edge of the market, exchange a book for some gold, then go buy some food and drink.