But the Wizard was undoubtedly a machine. She had not yet had the opportunity to study it in detail, but after her experiences in all of King Coyote's other castles, she suspected that it, too, was just another Turing machine. Her study of the Cipherers' Market, and particularly of the rulebooks used by the cipherers to respond to messages, had taught her that for all its complexity, it too was nothing more than another Turing machine. She had come here to the Castle of King Coyote to see whether the King answered his messages according to Turing-like rules. For if he did, then the entire system– the entire kingdom– the entire Land Beyond-was nothing more than a vast Turing machine. And as she had established when she'd been locked up in the dungeon at Castle Turing, communicating with the mysterious Duke by sending messages on a chain, a Turing machine, no matter how complex, was not human. It had no soul. It could not do what a human did.

The thirteenth tape was fed into the altar, and the machinery began to whine, then to whir, and then to rumble. The images appearing above the stage flourished into wilder and more exotic forms than any they had seen yet, and watching the faces of the priest and the acolytes, Princess Nell could see that even they were surprised; they had never seen anything of the like before. As the minutes wore on, the images became fragmented and bizarre, mere incarnations of mathematical ideas, and finally the stage went entirely dark except for occasional random flashes of color. The Wizard had worked itself up to such a pitch that all of them felt trapped within the bowels of a mighty machine that could tear them to shreds in a moment. The little altar boy finally broke away and fled down the aisle. Within a minute or so, the acolytes, one by one, did the same, backing slowly away from the Wizard until they were about halfway down the aisle and then turning away and running. Finally even the high priest turned and fled. The rumbling of the machinery had now reached such a pitch that it felt as though an epochal earthquake were in progress, and Nell had to steady herself with a hand on the altar. The heat coming from back in the machine was like that from a forge, and Nell could see a dim red light from deep inside as some of the pushrods became hot enough to glow.

Finally it all stopped. The silence was astonishing. Nell realized she had been cringing and stood up straight. The red glow from inside the Wizard began to die away. White light poured in from all around. Princess Nell could tell that it was coming in from outside the diamond walls of the keep. A few minutes ago it had been nighttime. Now there was light, but not daylight; it came from all directions and was cool and colorless.

She ran down the aisle and opened the door to the anteroom, but it wasn't there. Nothing was there. The anteroom was gone. The flowery garden beyond it was gone, and the horses, the wall, the spiral road, the City of King Coyote, and the Land Beyond. Instead there was nothing but gentle white light.

She turned around. The Chamber of the Wizard was still there.

At the head of the aisle she could see a man sitting atop the altar, looking at her. He was wearing a crown. Around his neck was a key-the twelfth key to the Dark Castle. Princess Nell walked down the aisle toward King Coyote. He was a middle-aged man, sandy hair losing its color, gray eyes, and a beard, somewhat darker than his hair and not especially well trimmed. As Princess Nell approached, he seemed to become conscious of the crown around his head. He reached up, lifted it from his head, and tossed it carelessly onto the top of the altar.

"Very funny," he said. "You snuck a zero divide past all of my defenses."

Princess Nell refused to be drawn by his studied informality. She stopped several paces away. "As there is no one here to make introductions, I shall take the liberty of doing so myself. I am Princess Nell, Duchess of Turing," she said, and held out her hand.

King Coyote looked slightly embarrassed. He jumped down from the altar, approached Princess Nell, and kissed her hand. "King Coyote at your service."

"Pleased to make your acquaintance."

"The pleasure is mine. Sorry! I should have known that the Primer would have taught you better manners."

"I am not acquainted with the Primer to which you refer," Princess Nell said. "I am simply a Princess on a quest: to obtain the twelve keys to the Dark Castle. I note you have one of them in your possession."

King Coyote held up his hands, palms facing toward her.

"Say no more," he said. "Single combat will not be necessary. You are already the victor." He removed the twelfth key from his neck and held it out to Princess Nell. She took it from him with a little curtsy; but as the chain was sliding through his fingers, he tightened his grip suddenly, so that both of them were joined by the chain. "Now that your quest is over," he said, "can we drop the pretense?"

"I'm sure I don't take your meaning, Your Majesty."

He bore a controlled look of exasperation. "What was your purpose in coming here?"

"To obtain the twelfth key."

"Anything else?"

"To learn about Wizard 0.2."

"Ah."

"To discover whether it was, in fact, a Turing machine."

"Well, you have your answer. Wizard 0.2 is most certainly a Turing machine-the most powerful ever built."

"And the Land Beyond?"

"All grown from seeds. Seeds that I invented."

"And it is also a Turing machine, then? All controlled by Wizard 0.2?"

"No," said King Coyote. "Managed by Wizard. Controlled by me."

"But the messages in the Cipherers' Market control all the events in the Land Beyond, do they not?"

"You are most perceptive, Princess Nell."

"Those messages came to Wizard-just another Turing machine."

"Open the altar," said King Coyote, pointing to a large brass plate with a keyhole in the middle.

Princess Nell used her key to open the lock, and King Coyote flipped back the lid of the altar. Inside were two small machines, one for reading tapes and one for writing them.

"Follow me," said King Coyote, and opened a trap door set into the floor behind the altar.

Princess Nell followed him down a spiral staircase into a small room. The connecting rods from the altar came down into this room and terminated at a small console.

"Wizard is not even connected to the altar! It does nothing," Princess Nell said.

"Oh, Wizard does a great deal. It helps me keep track of things, does calculations, and so on. But all of that business up there on the stage is just for show– just to impress the commoners. When a message comes here from the Cipherers' Market, I read it myself, and answer it myself.

"So as you can see, Princess Nell, the Land Beyond is not really a Turing machine at all. It's actually a person– a few people, to be precise. Now it's all yours."

King Coyote led Princess Nell back into the heart of his keep and gave her a tour of the place. The best part was the library. He showed her the books containing the rules for programming Wizard 0.2, and other books explaining how to make atoms build themselves into machines, buildings, and whole worlds.

"You see, Princess Nell, you have conquered this world today, and now that you have conquered it, you'll find it a rather boring place. Now it's your responsibility to make new worlds for other people to explore and conquer." King Coyote waved his hand out the window into the vast, empty white space where once had stood the Land Beyond. "There's plenty of empty space out there."

"What will you do, King Coyote?"

"Call me John, Your Royal Highness. As of today, I no longer have a kingdom."

"John, what will you do?"

"I have a quest of my own."

"What is your quest?"

"To find the Alchemist, whoever he may be."