books among the acolytes for decipherment. The acolytes were neither young nor old but in the middle of their lives, all dressed in white coats decorated, in golden thread, with the crest of King Coyote. Each also had a key around his neck. As Princess Nell waited, they deciphered the contents of the books she had brought and punched the results onto strips of paper tape using little machines built into their tables.
Then, with great ceremony, the thirteen paper tapes were coiled up and placed on a tremendous silver platter carried by a young altar boy. A pair of large doors was swung open, and the acolytes, the altar boy, and Princess Nell formed into a procession of sorts, which marched into the Chamber of the Wizard, a vast vaulted room, and down its long central aisle.
At the far end of the chamber was-nothing. A sort of large empty space surrounded by elaborate machinery and clockwork, with a small altar at the front. It reminded Princess Nell of a stage, empty of curtains and scenery. Standing next to the stage was a high priest, older and wearing a more impressive white robe.
When they reached the head of the aisle, the priest went through a perfunctory ceremony, praising the Wizard's excellent features and asking for its cooperation. As he said these words, lights began to come on and the machinery began to whir. Princess Nell saw that this vault was, in fact, nothing more than an anteroom for a much vaster space within, and that this space was filled with machinery: countless narrow shining rods, scarcely larger than pencil leads, laid in a fine gridwork, sliding back and forth under the impetus of geared power shafts running throughout the place. All of the machinery threw off heat as it ran, and the room was quite warm despite a vigorous draught of cold mountain air being pumped through it by windmill-size fans.
The priest took the first of the thirteen rolls of paper tape from the platter and fed it into a slot on the top of the altar. At this point, Wizard 0.2 really went into action, and Princess Nell saw that all the whirring and humming she'd seen to this point had been nothing more than a low idle. Each of its million pushrods was tiny, but the force needed to move all of them at once was seismic, and she could sense the tremendous strains on the power shafts and gear boxes thundering through the sturdy floor of the keep.
Lights came on around the stage, some of them built into the surface of the stage itself and some hidden in the machinery around it. To Princess Nell's surprise, a seemingly three-dimensional shape of light began to coalesce in the center of the empty stage. It gradually formed itself into a head, which took on additional details as the machinery thundered and hissed away: it was an old bald man with a long white beard, his face deeply furrowed in thought. After a few moments, the beard exploded into a flock of white birds and the head turned into a craggy mountain, the white birds swarming about it, and then the mountain erupted in orange lava that gradually filled up the entire volume of the stage until it was a solid glowing cube of orange light. In this fashion did one image merge into another, most astonishingly, for several minutes, and all the time the machinery was screaming away and making Princess Nell most anxious, and she suspected that if she had not seen less sophisticated machines at work at Castle Turing, she might have turned around and fled.
Finally, though, the images died away, the stage became empty again, and the altar spat out a length of paper tape, which the priest carefully folded up and handed to one of the acolytes. After a brief prayer of thanks, the priest fed the second tape into the altar, and the whole process started up again, this time with different but equally remarkable images.
So it went with one tape after another. When Princess Nell became accustomed to the noise and vibration of the Wizard, she began to enjoy the images, which seemed quite artistic to her— like something a human would come up with, and not machinelike at all.
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
