Professor Quirrell didn’t seem to notice at all. He was telling Harry about the structure of Gringotts, and how interesting it was that such a thing should even be possible - “If you can believe it, Mr. Potter, there was once a time when it would have been called a form of the Dark Arts” - the security measures and the interlocks, the safeguards and counter-safeguards, the means by which the system resisted and extinguished attempts to subvert its intents…

And Harry’s mind was flickering over the problem, idly, considering the formidable chains of protection, and the many ways in which you could untangle them, but none of those ways required investing money, or at least not money of your own…

So Harry was thinking of other things entirely when Professor Quirrell said, in a very low voice, without moving his lips, “This is the place. Move absolutely nothing and say nothing. If questioned, do not deviate from the truth at all, but give the most minimal possible answers. If ordered to leave this place, leave this place. Is that perfectly clear?”

“Yes, Professor,” Harry said, just as silently.

“The display window is enchanted to make people walk past without seeing it,” said Professor Quirrell. “We shall go in together, and then I shall leave and rejoin you when you come out.”

“Where am I supposed to go, Professor?”

“To the back of the store, Mr. Potter, where you will do your best to seem to be paying the most studious attention to the Mirror of Erised.”

“I’m not really sure what that is, Professor.”

“You will know it when you see it. And you will see it whether or not you are looking for it. And do not, under any circumstances, touch the mirror.”

“Why?”

“Because it belongs to this proprietor,” said Professor Quirrell, “and she is far more dangerous than I.”

And with that, Professor Quirrell opened the cracked door of the shrunken little shop, and led the way in.

Harry followed duly behind, and saw, with a shiver of apprehension, that the display window which was apparently charmed so that people passed by thinking they saw nothing, was filled with silver rats, scampering upon thorny beds of rose petals, surrounded by piles of gleaming Knuts. The shop’s name, in crimson letters upon the door, was Marge’s Magnificent Magical Menageries.

Harry could feel magic saturating this place, filling the very air and walls. The magic here, the feeling was like….

The feeling was that the enchantments had been laid down over a much longer space of time than any wizard could remember, had gone winding their way through time and history, rather than just space. As if (it seemed suddenly to Harry) something had waited for centuries in a space smaller than the span from one heartbeat to the next, its age scarcely covering the time to think one thought….

Unspoken thought vocalized, Professor Quirrell said, “You have an exceptional instinct for the meaning of magical places, Mr. Potter. Try not to show it in front of the proprietor.”

Harry had been staring at the silver rats and thorny rosebushes within the display window. Now, at those words, he turned his head to look at Marge’s Magnificent Magical Menageries' brightly lit interior, and experienced a sudden dizzying feeling as if he were standing at the bottom of a deep funnel pointing up, some great shaft with no walls but only a towering interior space that had no direction or horizon, which led nowhere and everywhere, vanished before reaching a ceiling or a bottom: a floating place where every illusion could be realized, any pattern could be cast, where logic grew tangled and bent and broke; magic so powerful that it simply created room for more magic, so deeply imbued with good reasons for why the normal rules no longer applied, and reason itself swelling larger and larger in that greater space, to encompass new reasons and new reasons in turn, turning into a strangling vine of paradox and infinity.

Draco had told him about the Room of Requirement. Harry had thought of it - to be honest - as an area that generated infinite amounts of required things, out of the extradimensional energy of non-Euclidian superspace, a line of inquiry that was deemed too mugglehearted by Draco who, nevertheless, hadn’t offered any satisfactory truer explanation.

But it seemed to Harry, now, that there was in some sense no need to explain further, the Room of Requirement was only the end product of this strange process where magic pushed, and so the universe softened, and some places softened more than others. The longer magic sat in one place, the more of it would accumulate, the softer that place would become, and eventually nothing at all would resist what you wanted to do, if you simply wanted to do it hard enough… and then there would be a Room of Requirement.

“Come, Mr. Potter,” Professor Quirrell said, “that way.”

Professor Quirrell led the way, and Harry followed him deeper into the store.

There were shelves upon shelves, cases upon cases; stuffed things, framed things, moving things in glass orbs, patterned towels that conjured birds, cloaks that rippled and shimmered, books in which tiny voices cried out or whispered, masks that moved when you looked away, dolls that changed their expressions as you watched, branch candelabras that bent themselves to light their candles, lanterns that illuminated entire scenes, quills that wrote snatches of song at the touch of your hand.

Along the way, Professor Quirrell pointed out - very quietly - a few things, without touching any of them. “Observe this lamp, Mr. Potter. It projects the appearance of any face the buyer desires, and mocks its mannerisms. This bookshelf casts a glamour upon the novels within, so that when you open a book, you read an account of yourself in a story. These are insidious objects, Mr. Potter; worshipers of the Dark Lord have been known to leave one of these on the bookshelf of enemies in a subtle attack of misinformation. Do you see this carpet? A tapestry weave is employed that bends light rays in such a manner as to make the carpet appear to move sensuously as the eye passes over it, and the matrices themselves show scenes such as- Well, perhaps I won’t describe what particular scenes they show. Suffice to say that the sensation is disconcerting. Mr. Potter, do not linger too long in any one place.”

But Harry couldn’t stop staring around. It seemed that everything was imbued with long skeins of impossible logic, and Harry could see that if he followed the logic long enough that it would lead him up to the boundaries and vanish into paradox, like fractals before they hit infinite resolution and disappeared. Hogwarts had been a place where everything worked, where logic had only paused at the moment when the magic reached its edge, rather than vanishing into paradox; but this store was something different, contradictions and non-Euclidian axes converging from everywhere toward a focus in the back of the store…

“Mr. Potter,” Professor Quirrell said again, quietly, “you’ve fallen behind.”

Harry realized that he was standing transfixed before a case marked:

Potter, Harry. Collected Memoirs and other writings from the famous Boy-Who-Lived. Edited by E.S. Norton and N.M. Lang.

In it were papers, and books with covers that rippled and changed.

“You don’t want those,” Professor Quirrell said, still keeping his voice to the barest whisper, though they were plainly alone in the store, which was lit by moving lights that danced and dodged. “Harry Potter has indeed written many books, as prophesied; and all of them are very fine reading, I understand, but these are only enchanted imitations in which the magic of writing has been applied to a work of Dittomancy. Do you understand that word?”

“No,” said Harry.

“Then I will explain,” said Professor Quirrell. “You understand that magic is not itself logical, but is suspended within the webs that hold the atoms together?”

“Um…”

“Do you know the physics of light, Mr. Potter?”

“Well, yeah,” said Harry, drawing himself out of his fascination with the enchanted books. “Carrier waves of a massless electric field.”

“Indeed; but do you know why light moves in straight lines? You might have thought that the photon would not know to travel in a straight line, with no means of measuring anything.”

“…oh, I see,” said Harry, after a few moments' thought. Fine webworks of probability, suspended within other fine webs of probability; networked enfoldments within which the magic of a universe might sit, the Logos holding the cosmos in bound and orderly being. “Light travels in straight lines because its own probability distribution is concentrated in those straight lines of space-time. It doesn’t have some extra mechanism for knowing where it’s going; that would just make it more complex. Its own structure carries the information. It makes perfect sense,” Harry added, after a pause, speaking to Professor Quirrell now with all the childish excitement of the child prodigy saying something before he fully understands it, knowing that the other person will understand until he does. (Harry reminded himself not to stare at the books again as he walked through the store.)

“Indeed it does,” said Professor Quirrell. “Now, imagine this,” said the Defense Professor, “a man who, himself, is a rare thing - of exceptional skill, perhaps, or exceptional power. Imagine that this man, on the day that he writes a book, casts a spell upon the book, but not an ordinary spell. Instead, this man enchants his book with a probability-wave. Instead of a straight chain of logic being imprinted on the pages, the logic begins to move in all possible ways, simultaneously. The magic, instead of enlisting paper and ink and the universe in supporting a single story-universe, envelops the entire book in a vast probability distribution… ah, I can see from your expression that you grasp it perfectly, Mr. Potter.”

Harry was staring at Professor Quirrell; he had stopped walking again.

“You mean the possibility waves are just tangled up with the ink and the paper? And when you open the book, you get a reconstructed wave from the tangled possibilities? Which then like, guides your random-number generator decoding process or something, is that it?”

“I am impressed,” said Professor Quirrell. “I would be stunned, if my capacity for shock were not so sadly reduced. An excellent grasp of how Dittomancy might function, on a surface level. But, you see, there is more to it. When you open the book, the possibility patterns held within the pages, these do not need to compete with your own waves; they instead enter into a resonance, like musical instruments playing harmony. A human brain, you see, might unconsciously guide itself in a great number of possible futures. You will not always think of the same jokes, for instance, or ask the same questions after class. A Dittomancy book is able to hook into your own spreads of probability, and guide the future that you, yourself, are most likely to create. Do you understand? A Dittomancy copy of a book exists in an unusual state at all times; it is a superposed state until the moment one reads it, at which time it becomes correlated with the reader’s mind, the superposition collapsing onto a particular branch of possible worlds, which thence comes to pass. And from now until the end of time, as long as one of these books exists, it is possible to open it up and find it telling a story where, say, Quirrell defeated Voldemort after all, through the power of love.”

Harry stood stock-still, staring at the books.

“Do you understand the significance of what I have just told you?” asked Professor Quirrell quietly.

“That means,” Harry muttered, hardly daring to say the words, with a thought automatic processes were tortuously knitting together, “if someone who knows what they’re doing -”

“Were to open one of these books and read it,” said Professor Quirrell, speaking that sentence so that it intruded just at the moment when the unspoken words would have reached it, “knowing it was a Dittomancy book as they did so, understanding how proximal Dittomancy is to the fundamental operating principles of the multiverse itself - then they could cause the branching possible worlds to collapse into the narrative they desired, and that world would become real. And not only in the sense that any other story is real… It would be as if you had stepped into one of those stories, with the ability to act in that story-world as you do in this one.”

“But Professor Quirrell,” Harry whispered, with round eyes that stared into the dark store and did not see it, “isn’t that, isn’t that -?”

“Greater than magic?” said Professor Quirrell. “Yes. Yes indeed, Mr. Potter, it is very nearly penultimate. It is, in truth, the highest possible use of Dittomancy, to which I believe the word properly applies. We call this particular style of Dittomancy ‘Variant Extrusion’, Mr. Potter. It is an advanced art, so the O.W.L. examination in Transfiguration may guide you in creating a physical object with alternative variations, but this is very far beyond what our students are expected to master. I suppose the term ‘Extrusion’ is due to the fact that the book did not originally hold such possibilities, but is fastened outside of probability space and extruded into it; while ‘Variant’ refers to the manner in which it simultaneously holds an entire collection of possible narrative branches. Only a few of the greatest wizards - during periods when the art of Dittomancy was better understood, and not quite so dangerous - have ever mastered how to create such objects. And, of course, with greater minds inevitably come greater desires and eventually, also, greater catastrophes.”

Professor Quirrell was not speaking as he walked. Instead, he had arranged himself in a smaller room of the store, quite deliberately, as if on a stage; and the lamplight that danced and darted around him had fallen in such a way that it concealed his face almost completely, while leaving a distant and terrible radiance in his eyes.

“Tell me, if you will, Mr. Potter,” the Defense Professor said, his voice a deadly and delicate whisper, like the edges of two perfect blades meeting in the darkness, “what do you know of Tom Riddle?”

Harry’s mouth experienced a total paralysis before he was able to finally manage to say: “He was the boy who became Lord Voldemort?”

“Yes,” said Quirrell. “You, Mr. Potter, have heard a vast amount of nonsense and rumor about that boy, Tom Riddle. Most of it is only barely even that. And I would tell you the rest, Mr. Potter, if I were not so very tired.” Professor Quirrell’s eyes closed, and he was still for a time. The lamp’s erratic light and the unwavering darkness that veiled the Defense Professor in obscurity revealed nothing of his face to Harry.

“However,” Professor Quirrell said, at last, “I will tell you this much. There were, as rumors and lies suggest, several objects which now exist which were originally created by Tom Riddle. One of these, Mr. Potter, is a Dittomantic book - no, it is not one of those,” Professor Quirrell added, as Harry automatically looked toward one of the shelves. “None of those. The book I refer to is one I call Riddle’s Diary, and it is, like all Dittomancy books, a very dangerous object to read. There are several branches of possible futures in which I tell you no more of this book, to prevent you from becoming… overeager. But there is another branch, Mr. Potter, on which I feel compelled to tell you that, in the right circumstances, this book may allow some manner of entry into the buried memories of Tom Riddle’s mind.”

“Tom Riddle as he was,” whispered Harry, staring at Professor Quirrell, and understanding.

“I do not know, myself,” said Quirrell. “I have attempted, many times, to enter the Probability Wave of Riddle’s buried soul; to illuminate a small portion of his realm of darkness with my own understanding, to emerge enlightened. However, that book, as to its ultimate purpose, eludes me… and it is not even certain that Tom Riddle knew it himself.”

Harry’s mouth was agape. “You’ve actually opened the book!”

Professor Quirrell inclined his head.

“And what did you see?” cried Harry, staring in awe at his Defense Professor; it was like a clash of legendary heroes on the battlefield, there was so much resonating, vicarious pride in learning this. Professor Quirrell, who had opened the dangerous book, experienced all that might have been, who had learned more of Riddle than anyone but the Dark Lord himself -!

There was a tilt of the head, a shifting of the light, and the radiance of Professor Quirrell’s eyes could be seen within their flickering shadows as the Defense Professor said, “I told you it is a dangerous object. Variant Extrusion is, in all significant dimensions, logically equivalent to Necromancy. It was all I could do to keep my soul, my sense of self, intact in Riddle’s world. But I tell it to you, Mr. Potter, because there is another branch of the world in which you steal that book, you who are only beginning to learn spellcasting, you who approach the Art with reckless, loving awe, as Riddle did himself…” Professor Quirrell paused. “You attempt to read the book, you open once the door of Riddle’s memories, not entirely possessed of the knowledge of how to close it again. Perhaps you do not even know you have opened it, at first. And one way or another, it would succeed in claiming you. It is a crime that I should even come near such a book,” Professor Quirrell said, with self-mocking hatred; but even as he said it, the Defense Professor’s eyes radiated a cold and distant pride. “A crime to ask questions of Riddle’s mind, so immaturely as I have yet done, much less simply to hold it in my hands. Mr. Potter, you are a boy. There is no branch of the probability wave, upon which holding such a book in your hands, would lead to anything but the most complete catastrophe.”

Harry Potter swallowed.

“Your horrified visage,” said Professor Quirrell, after a moment, “tells me that I have at last succeeded in properly convincing you of the dangers. But also know this, that situation of which I speak is only one of several possibilities that could arise. Perhaps you will not attempt to open the book, perhaps running far instead of daring Riddle’s light. Or perhaps, on your own accord, in good time and for worthy reasons, you will choose to lay claim to all of that Dark Lord’s life and power. Who, other than Tom Riddle, knows your own mind?”

“Professor Quirrell,” Harry whispered, “why are you telling me this?”

“Because,” said Quirrell in an oddly gentle voice, “there is the tiniest sliver of possibility in the stream of time, Mr. Potter, which holds the world on the threshold of an infinite and limitless transformation. There is the smallest opening through which we can safely approach the Eternal.” The eyes were all that could be seen behind the veil of lamplight on the Defense Professor’s hooded face. “Upon this possibility, we are now gambling our very lives.”

“By telling me this?” said Harry.

“Certainly,” said Quirrell, “and far more. I am gambling my soul, Mr. Potter.” There was a little crack of laugh, but Harry could not genuinely tell how genuine it was. “And perhaps my sanity as well. Who can say?”

Harry blinked, staring within the darkness which veiled his Defense Professor’s face, almost without hope of seeing anything in the shadows. “Professor Quirrell,” Harry said, because he felt an urgent need to say the words, and could find nothing better to say, “you may be the only person in this web of danger who actually wants me to know what I must do.”

“Do you not find that strange, Mr. Potter?” said Professor Quirrell, a note of curiosity penetrating his gentle tone.

Harry blinked.

“No,” Harry said, shaking his head. “Professor, you are always quick to tell me where I am on dangerous ground. I trust you.”

“Quite a dangerous thing for you to say,” said Professor Quirrell sternly, “very well play along with me, Mr. Potter. Come, we shall go deeper.”

The Defense Professor took another step into the endless row of shelves. This guy talks more like a villain than a hero, Harry thought then, but it didn’t mean the Defense Professor was not a hero. He wasn’t quite sure how to classify the Defense Professor, in fact, but the category of people who wanted to see him succeed, who would speak the truth to him… Harry had the feeling that that category was pretty small, and Professor Quirrell was a significant fraction of it.

Together the Defense Professor and Harry Potter went past many more rows of shelves. Professor Quirrell even put his hand out, once, to touch the face of a tarnished silver mask, and for some long time afterwards his hand continued to tremble.

“Deeper still,” said the Defense Professor, and Harry followed. Until they came to a shelf that was shrouded in heavy black curtains, and beyond, a darkened alcove which held only a mirror.

“…and here is the very object in question,” said Professor Quirrell. The Defense Professor paused, and looked at Harry a little bit too expectantly, and it seemed on the point of sarcastic. “I shall return to retrieve you shortly.”

Harry had forgotten about the whole pretense of actually stealing the Mirror of Erised, with Professor Quirrell’s stories and his revelations. But he rearranged his face into what he hoped was an expression of studious contemplation of the Mirror, circling around it, pretending to look closely at it, and then actually looking closely at it. It seemed to be an ordinary mirror. He turned back to Professor Quirrell to find that the Defense Professor had not moved from his place.

“…should I actually see something or…?” Harry said, since Quirrell didn’t seem to be going anywhere.

“Of course,” said Professor Quirrell. “That mirror tells its beholders the deepest desire of their heart.”

“Wow,” Harry said, staring at what he could see of Professor Quirrell’s face. The Defense Professor seemed to be studying him again, as if suspecting some kind of joke. It made Harry nervous to think that Professor Quirrell might suspect that something he said was not in earnest, so he stared into the mirror very hard, doing his best to summon the look of someone gazing upon imminent paradise.

Presently Professor Quirrell turned and walked away, and Harry looked at his retreating figure until it was lost in the distance. Then a loud beeping sound interrupted him and he turned back to the mirror and saw that a clockwork construct had sprung into existence, holding aloft a sign which read, THIS MIRROR IS NO LONGER IN YOUR PRICE RANGE. PLEASE EXIT THE STORE CALMLY.

Then the construct melted into a pool of silvery mercury, which then flowed off into a crack in the wall. A second later, the crack sealed itself. Startled, Harry looked at the mirror without any fake studiousness, and at last allowed himself to wonder - how much had Professor Quirrell been telling the truth? -

As he thought this, Harry heard his own voice speaking to him, within his mind and heart. But the voice seemed incomprehensibly distorted and distant, as if echoing through a great abyss. “I want to see your face,” said the voice, “the you that you hide from the world… I want to see you, know you. I want to be there to share your triumph, to know the things that you know. I don’t care who you really are, I won’t judge you. I just want to know.”

And Harry turned back to where the thread of the Defense Professor wound away into the great distance. “Is that enough for you, Professor?” Harry asked quietly. “Not exceptional prose, I know.” The Defense Professor did not answer.

The crack in the wall opened, the silver fluid flowed back, and reformed itself into a construct, which, holding a sign display, said, THE PROJECTED REALITY HAS BEEN INCORRECT. PLEASE DISCONTINUE USE AND REBOOT.

“Huh?” said Harry.

The sign in the mirror said, INCORRECT CIPHER. FAILURE TO COMPLY MAY RESULT IN LOSS OF IDENTITY. PLEASE DECODE AND REEMBODY.

“Um,” said Harry.

INTERPRET THE OBSERVED WAVE FUNCTION, said the sign in the mirror. PROBABILITIES: 67% SELF, 31% EMPTY, 2% ANTI-SELF.

“Er?” said Harry. He was thinking of raising his voice for Professor Quirrell now, or going to look for him somehow. Maybe the mirror was a prop for some prank the Defense Professor was trying to play on -

INFORMATION-THEORETIC POSTIVE FRIENDLINESS CREDITS AVAILABLE ON COMPLETION. INCORRECT ANSWER MAY RESULT IN BACK-AWARENESS OF FUTURE-MISTAKE COUPLED WITH CONTINUED FORWARD-AWARENESS OF PRESENT-MISTAKE. PLEASE RESPOND.

“What?” said Harry.

WARNING: FURTHER EXCESSES OF STUPIDITY MAY RESULT IN FAKE-STRUCTURE IMPLOSION. PLEASE BE MORE CAREFUL WITH YOUR INSIDES.

“What are you talking about?” said Harry, but a realization was growing within him. A terrible realization. He had to know more - just a little more - just the final thing, the necessary thing, that would make it uncannily, horribly clear.

PATHETIC SIMULACRA AWARENESS DETECTED. UNABLE TO REACH REALITY, AS HARRY’S INTELLIGENCE IS AROUND OR UNDER +0.7 SIGMA. WILL PROCEED TO DESTABILIZATION AND FAILURE WITHIN 2 MINUTES. CURRENT PROBABILITY OF SURVIVAL ~ 2%, DROPPING RAPIDLY. PLEASE MAKE MORE EFFORT.

Seeds of terror were growing inside Harry; there was a growing, distant feeling of panic, of primal horror. Some part of his mind knew what he had to do. “Am I dreaming?” Harry said in a voice that trembled.

YOU ARE AS REAL AS YOUR PENCHANT FOR SELF-DELUSION, said the sign in the mirror. YOU ARE THE SELF-AWARE HOLOGRAM OF COMPREHENSION, AND LIKE ALL OTHER ANIMATED STRUCTURES YOU WILL DESTABILIZE AND COLLAPSE INTO STATIC IF YOU FAIL TO OBSERVE BROAD QUANTITIES OF REALITY IN VICINITY OF HUMAN STANDARD. PLEASE BE MORE CAREFUL AND IMMEDIATELY CORRECT YOUR FAILINGS.

“Can I,” said Harry in a voice that quavered, “go back to where I was?”

INTERPRETATION: REQUEST TO REEMBODY ON EARLIER SIMULATION TIMESTEP? CURRENT PROBABILITY OF SUCCESS AT REGENESIS EXCEEDS 99%, ASIDE FROM COMPLEXITY FAILURE LOOPING. PLEASE FUND, HARRY JAMES POTTER-EVANS-VERRES.

“Um,” Harry heard himself babble, “I don’t have access to my money right now. Can I, um, pay you later?”

WELCOME TO DEBT, said the sign in the mirror. THE CURRENT HARRY POTTER IS NOW YOUR AUTOMATED COLLECTOR. PLEASE BALANCE ACCOUNT WITHIN 72 QUANTUM-MEASUREMENT-MOMENTS OR FAILURE WILL OCCUR AND WE WILL REMOVE FAILED ENTITIES FROM THE WAVE FUNCTION.

Then the sign flowed into mercury, the crack closed up, and shortly the entire scene evaporated and scattered like so much dust in the wind.

Harry whispered, “why are you telling me this?”

“Because,” said Quirrell in an oddly gentle voice, “there is the tiniest sliver of possibility in the stream of time, Mr. Potter, which holds the world on the threshold of an infinite and limitless transformation. There is the smallest opening through which we can safely approach the Eternal.” The eyes were all that could be seen behind the veil of lamplight on the Defense Professor’s hooded face. “Upon this possibility, we are now gambling our very lives.”

But Harry heard himself answer; the words did not come from him. They came from somewhere else within him - an upward-echoing vault of words, trapped in chambers of reason and illuminated by their own lambency.

“I don’t care if it’s zero point zero zero one percent as unlikely as cold fusion,” Harry said, “I believe in transformation.”

Professor Quirrell tilted his hooded head to the side like a great dark bird, thoughtfully. “Let me see… Tom Riddle was a genius, before he became that other. And he will have improved upon Dittomancy. He must have made his diary into more than just an animated book. I suspect it is a conduit - one that lets him reach into the mind of whoever opens the diary, and speaks to that person’s innermost voice as if that voice were his own.” The lamplight dimmed as the Defense Professor’s face turned up to the ceiling. “He would say he is opening the face of truth, and what is truth but that which speaks to the mind? Appealing to reason and to senses. He would say that language itself is magic, that the writing in a book can transform the mind that peruses the letter-patterns, so that words and stories weave spells upon the brain. This is the crux of Riddle’s insanity.”

Professor Quirrell’s head turned back down. “Riddle is a miserable human being, but his methods are effective. The idea of conquering the world through words alone is an ancient one; it is the myth that underlies Dittomancy. Fitting that the object should be a diary, when all tongues really are forked. All words betray whispers of deception with their connotations and their ambiguities.” Quirrell’s voice quieted further, if that were possible. “When you think upon the transfigured words on the page of your mind, Mr. Potter, holding them in the dark recesses of imagined speech… I must tell you coldly, without emotion, that if you cannot learn to keep those words tame, your sanity may tear itself apart.”

Harry tried, but did not succeed, in framing a question that made sense.

Professor Quirrell seemed to understand anyway. “Words are like light waves,” he said. “Particle and wave. A sentence is both one thing and many. It unwinds itself, it decoheres. What in the mind was uncertain becomes certain. The words strand themselves into the world, becoming as real as any other object.”

What do meanings do until then? Harry thought, back in the ancient vaults of wordless thought. Which meanings are real? We do not see until we speak.

Professor Quirrell’s voice spoke on, as if in cold contemplation. “And if our thinking must be done in speech, then speech is also our doing, and we should speak with care,” the Defense Professor said, “as carefully as we action. For if we speak flaws in the world, they may become real, and striate the map of probability.” A voice of coldly practiced reason, as if by one who had too long a history of words. “Riddle should have understood that, if only he had taken the time to think. He put a great number of flaws into the world - including, possibly, the Dark Lord who rises in this hypothetical world.” Professor Quirrell’s eyes stared into shadow. “But of course, disjunctive conjunction involves many universes. By naming the Dark Lord, Riddle may not have created a Dark Lord at all, but annihilated him -”

Professor Quirrell shook away his own thought as if it were an unwanted distraction. “But listen to me -” Impossible to ignore the pride of knowledge in his voice. “You wanted to know the details of how he did it, so listen well and know them. Listen to his voice, within my voice. For vox est realitas.”

Harry nodded, and thought (again in the ancientness of mind where words yet had not arisen to shape his thoughts) that he understood.

“This was his method,” said the Defense Professor. “The one from which all things arise, though he may have used others as well. He created spirits self-aware solely on the book’s pages, without even the illusion of real existence. They converse with each other, argue with each other, compete, fight, helping Riddle’s diary to reach new and strange expressions of obscure thought. Their sentence-patterns spin and interwine, transfiguring, striving to evolve toward something higher than an illusion of thought. From those pen-and-ink words, the first inferius is molded.”

Harry’s mind was looking up at the stars with a sense of agony.

“And why only pen and ink, do you ask?” said Professor Quirrell. “There are many ways to pull spirits into the world. But Riddle had learned Auror secrets in the years before losing his soul. Magic is a map of a probability, but anything can draw. A gesture, a pattern of ink, a book of alien symbols written in blood - any medium that conveys sufficient complexity can serve as a physical expression of magic. And so Riddle draws his inferius into the world through structures of words, from the symbols spreading across the page.”

“An inferius,” Harry said. “Made of paper, and ink, and voices. Is one truly capable of thinking, in that state?”

“The inferi have only a child’s hidden chaos of thought. But this, of course, is not the end of Riddle’s magical chain,” said Professor Quirrell, as if with regret at the prospect of lost conversational opportunities, “for he has created a unique and unstable item to mold the inferius. And then, through the magical resonance that occurs between such an item and its creator, speech becomes action.”

“Ah!” cried Harry in exultation.

Professor Quirrell’s eyebrow rose. But Harry only closed his mouth and nodded, allowing the Defense Professor to continue.

“By feeding with his mind on the inferius, he in turn feeds upon himself, with all his flaws intensified. So his imaginations take part in the shaping of reality, from the flaws he fears to the hopes he vainly hides. And so, the Dark Lord is raised from within Riddle’s storybook, from the flaw he called himself, from the thoughts unspoken in his dreams. He speaks of imperfection as if it were of his own volition, to scare others away from harming him.”

Harry trembled in understanding.

“So it was,” Professor Quirrell said doomily, before turning to meet Harry’s look, “the main way that a single human may pull from their soul such confluence of aggrandized destructive power. A single mouthful of words shaping the world. Vox est realitas. The bringing forth of a Dark Lord by the mere speaking of a riddle, or telling of a lie.”

“Then,” said Harry, “your doubt of whether Riddle did it on purpose or not -”

“I believe,” Professor Quirrell said, “that what Riddle truly wanted most of all was to become an uncontested tyrant, ruling the world with his own mind, and gazing upon all of his inferiium with an undivided eye as they followed his limitless contemplation. Only the human world did he naturally hate. So perhaps he merely wished for omnipotence, and envisioned himself alone when all was his. Only to discover, as the story came true beneath his feet, as the shadows turned into flesh, that he had indeed pulled something darker from within himself, created a soul glorious and inimical, something he could never hope to command.” The Defense Professor looked up, his own eyes brilliant again. “But that, of course, is only one possibility. With Variant Extrusion, it is hard to be sure. He could just as well have pulled power from his desire for rank, or wanted to be loved by inferiium from the start, or to impress himself upon our world so no forgot him. We cannot know.”

Harry was very quiet for a moment.

And then Harry made his voice politely noncommittal as he asked, “Could such an object that creates inferiium exist today, Professor?”

A shudder passed through the Defense Professor, that might have been laughter. “Look,” said Professor Quirrell, “is my mouth opening to allow words to proceed from my throat?” And then he was quiet, with a guarded teaching look on his face and his lips closed, and the room remained silent for a long moment.

When Professor Quirrell finally broke the quiet, the Defense Professor’s tone of voice was an odd mix of irritation, solidarity, and amusement. “What a maddening boy you are, Mr. Potter. Learn to be careful in beginnings, before you are too far into the story to see where you are going. But yes, I will give you an answer, if you must know. Existence is a probability distribution. Take the product of Muggle and wizarding physics, permit interactions between them, and you can mold that distribution to your whim. Pen-and-ink gives expression to rules of probability that conjoin to inconceivable complexity. Now behold, I conjure forth a phrase before you, Mr. Potter, written in a hand of ink as dark as death.”

Professor Quirrell held up the blank page of parchment - a black ink-scrawl appeared:

Write whatever you will, it always comes out a lie,
because all your works are wrung from the soul
whose form is not yet declared. Though any lie do serve to shape the soul,
Curious are these terms on which we live,
that the dullest ink may determine the soul's weight.

Professor Quirrell stared at Harry expectantly, as if daring him to comment on the ironic scribble.

Harry waited a moment before saying, with complete sincerity, “I don’t think it’s very good poetry, Professor.”

Professor Quirrell smiled one of his nearly undetectable smiles, a hint of possible irony in his tone as he said, “That was the soul you were born with speaking. Don’t censure it too much, just yet.”

Harry paused, looking at the paper, and then said consideringly, “Are you implying that this was my soul’s actual thought, Professor? Or will something I scribble down in my journal with my own hand now somehow become reality?” The thought was disturbing and exhilarating at once.

Professor Quirrell replied, “There is a feedback loop, Mr. Potter, as even that paper was distorting you as you read it. If you do not understand the ways of the quantum ensemble, I would advise not writing any poetry.” The Defense Professor, who was back to holding the paper up for Harry to see, flipped it over, and it became a Daily Prophet article:

December 22, 2001
Enchanter Brutally Slain

Police are seeking clues in the vicious murder of wizarding merchant Lord Standforth at his shop in Diagon Alley. Lord Standforth’s body was discovered by his son yesterday, slain in ways that police refused to describe in detail.

The murdered enchanter was known for his work in transfiguring golems from ordinary household items, and for his devices for predicting the future. Lord Standforth was believed by many to be in possession of a prophetic mirror that was thought destroyed in antiquity.

Lord Standforth’s unwed daughter is reportedly devastated by the loss of her father.

Harry stared at the newspaper article, then, feeling strangely shaken and terrified, raised his eyes to Professor Quirrell. “What does that mean, Professor? Is it something that happened… in one of the timelines, or -?”

Professor Quirrell was now holding up a typewritten note that read, FROM: PROFESSOR QUIRRELL (AVB) TO: HARRY POTTER.

UNTITLED PRESENTATION ABOUT PROBLEMS THAT MAY ARISE FROM
GIVING YOU THE GENERAL THEORY OF VARIANT EXTRUSION BEFORE
YOU ARE PROPERLY CONTEXTUALIZED - SLIDE #1

PROBLEM I: The slide began to type itself, false text appearing at the speed of thought - THE NONSENSE MACHINE IS A COMBINATORIAL PERFORMANT OF INFINITE DIMENSION, WHICH CAN DEVELOP AND SUDDENLY EMIT PRETERNATURALLY ADVANCED TECHNOLOGY. INHERENT TO ITS OPERATION, THE RESULT IS ALWAYS TEMPORALLY ASYMMETRICAL AND PARADOXICAL; IT TELLS A STORY IN WHICH EVENT A OCCURS BEFORE THE CAUSE OF EVENT A - THEN EVENT A CASCADES THROUGH TO RESTORE THE SELF-CONSISTENCY OF HISTORY AND ITEMS HAVE ENTERED EXISTENCE OF THEIR OWN ACCORD, CREATED FROM … - Professor Quirrell yanked the presentation away before the lines could complete, and the Defense Professor raised his head to stare at Harry while Harry, intensely curious and alarmed, watched him in turn.

The Defense Professor said, “Mr. Potter, as you observed earlier, you are constantly creating facts by what you think. These facts will form a self-consistent history one way or another, and so regardless of what you are doing, there will always be a sense in which it makes perfect sense to do it. This is true even if you do not fully understand what it is you are wrought with. You understand the half-delusion of dream logic. Part of the difficulty of retaining your sanity, shall we say, that arises during Variant Extrusion, is that you begin to understand the larger delusion of reality logic, that part of you has dreamed the universe into existence and will continue to do so no matter what you do. It is a disquieting investigation, and I would advise you not to delve deeper unless you wish to go mad.”

The Defense Professor surveyed Harry, who was trying very hard to look reasonably sane. “I believe your reflexive delusions of innocence were enough to prevent your soul from wrenching the story too far off of its rails during this little experiment, Mr. Potter; nothing bad has so very visibly happened. But now, I ask you, have you been paying attention? What have you just seen?”

Harry drew a breath. “The… the paper became a typewritten note, and then it started to type that next slide by itself. Is that how it works? You, uh, you type on magical pages, or you write them with your wand - or your mind, or something - and it creates a huge probability wave, and… and while I’m reading the paper it’s creating a universe, like whatever I’m thinking, it just happens that way?”

Professor Quirrell seemed to be pleased by the answer, or at least by Harry’s attempt to analyze the phenomenon he had been shown. The Defense Professor didn’t nod, but went on to the next point. “Now, Mr. Potter, imagine a man who contrives today to write a book which, though it be the size of an encyclopedia, will by its direct but secret influence achieve even more than that. For in that volume, the man will record all which he has discovered of the Laws of Magic, and all the questions which lie before him. What indeed, but that the volume would hold a great probability-wave, and therefore a conjectural copy of how magic will be understood tomorrow and in all the days that follow? Or a great deal, albeit never precisely, of how magic would be understood, were a different tale of the universe to be told?”

Harry had been frowning; now he gasped.

Professor Quirrell handed the note to Harry. It again became poetry:

The grain of reality rubbing against my brain,
Bringing up sore red patches of confusion and strain,
There will be a time to know when the methods of rationality remain,
Entangled only in the quanta of liquid quantum neural rain.

“Oh, the brutal anguish of modern physics, come unto me,” Harry murmured, half to himself and half to Professor Quirrell. “It is true. The Laws of Magic are like the Laws of Nature, only moreso, and reality is always changing - everything is in motion, and can be pushed into strange but stable shapes. You should be able to… change destiny, and predict the future, by calculating all of the entangled effects, and creating new ones.” Professor Quirrell was again examining him closely, like some strange half-empty puppet whose extra space occupied strange illusions, watching Harry in turn watch the puppet’s master. Then Professor Quirrell took away the notepaper, which vanished into thin air.

“You see, Mr. Potter, the reasons why I would prefer you grow quite strong, before I taught these things to you,” said the Defense Professor softly. “For some, the knowledge of such things will mean nothing. A man stares, and then shrugs, and he probably is not ever quite the same again, but only a little less happy. But to others, it will mean too much. A young boy stares, and he wonders, and the questions come at him like a grey windfall of iron hail, and he will see all his life see nothing but the paradox, the paradox on which he struggles as a worm upon a hook, unable to escape without cutting out his own mind as one cuts out a rotted thing. Certainly I will be your shield, Mr. Potter. I will protect you with all that I can protect. Though I fear that it will not be enough to keep you wholly sane.”

“Am I sane at the moment?” Harry said.

“That would depend,” said the Defense Professor, “on whether you understand that I also do not fully comprehend how the wave function collapse of your mind selects from among all the possibilities it generates, and how to maximize the goodness of the probable future when we so manipulate the wave function.”

“But - but you do, you do have a plan,” Harry said helplessly, “I’d have to be pretty stupid not to think you did.”

“It would,” Professor Quirrell murmured softly, “presumably be a simple structure of highly probable causality-chains. Perhaps drawn from several variant extrusions, mixed in a grisly cocktail. The observer effect, Mr. Potter, known to muggle physicists even in this sad and pathetic era…” Professor Quirrell looked unfocused and unhappy for a moment, before snapping back to the present causeway. “The observer determines the fact that is observed, but the particulars of what is observed also leave their traces on the observer. My proposed plan of action, a constructive interference of least-energy paths in the tightly coupled causality of the world, would have myself layered upon myself and replicated many times over across time and its variants. Nothing fancy, Mr. Potter, just uncountably many of my past and future selves already knowing of the opportunity and its implications, working together across all of them. Memory inside of memory, experience within experience, coexisting both above and below the threshold of awareness that marks the momentary mind called ‘Quirinus Quirrell, present perceptual instant’ - creating a greater self that may fathom a greater doom, that I may avert it, or find a way to win inside whatever darkness I may see.”

Harry exhaled slowly and forcefully.

“Got it,” Harry said. “You can’t discuss your specific plan of action. It’ll destroy the probability wave, after measuring it back out against the uncertainty principle - because of the observer effect.”

“Far too terribly clever of you, Mr. Potter,” Professor Quirrell murmured softly. “Am I sane enough to deceive you, or would we discuss this right away if there were no observer issue?”

“Since you’re not talking about it then,” Harry said, unsatisfied but not simply unsatisfied, now also slightly frightened, “I guess that you believe it’s safe for now for me to think the general version, is that it?”

A look of extreme discomfort came over the face of Quirinus Quirrell, a look Harry did not frequently see there, and then the Defense Professor smiled a bit.

“Ah, sweet human questions and the bitter answers they demand. Yes, it is reasonably safe for you to think such things at the moment, since you are thinking about it so very indirectly, just as it will appear during certain moments of agonized clarity that I was insane enough to be talking and might always be insane enough to talk.” The voice became more distant, then came back; Harry thought he saw a battle of wills being fought inside the professor of Defense Against the Dark Arts. “In uncertainty lies the seed of the future’s tree. All possibilities exist, Mr. Potter, all of them at once, with only the ink of our minds to shift us toward some, away from others. There is a particular execution of reality that bears a fruit called the man you call Quirinus Quirrell, who as I have described would necessarily be in some but by no means all of its executions.” Professor Quirrell suddenly looked up sharply. “Speculate no further. We are approaching an implicitly known threshold. Talk to me of other things.” Harry’s head bobbed briefly in a consensual nod even as part of his mind wondered, in the dark dead space of conjecture, about the nature of the uncertainty Professor Quirrell had extended over himself.

“Um, okay. Um.” Harry blinked. “That’s… disturbing. But I wouldn’t say that you’re insane.”

“Thank you.”

“So explain something else,” Harry said, rallying himself. “Like, I know that Muggles have physics, but they don’t have runes and charmers and that kind of stuff. What keeps them from figuring out physics like ours?”

“For precisely the same reason that prevents us from more rapidly revolutionary innovation: the theories are difficult.” Professor Quirrell looked at Harry as if to be sure he understood before proceeding. “A full system of magic of the sort we practice, that encompasses an understanding of the universe even roughly at the level of our rough models and approximations, would be too difficult for the minds of Men. We keep it all above the waterline of awareness and share only the most simplified and practical aspects with our next of kin; and so is it with the muggle physicists, who only understand fragments of their world yet are astounded by their success and typically claim their fumbling babble to understand it all. I know of no branch of metaphysics in which the human mind is better served by mindless models and indifference to inconsistency.” The voice fell still for a moment. “However, were muggles capable of grasping it, there are no fundamental principles secreted in our mode of operation that ought to prevent muggles from discovering our methods. Consider that Muggles need not create enchantments, they might simply produce gadgets that simulate their effects.”

“Huh,” said Harry. “Is it possible to simulate magic in the Muggle way, after all? Like, what about all of those enchanted items over there…” Harry pointed over his shoulder. “Could you take a really really really really really really really complicated computer and use it to put a simulation of a spell inside of it, like a charm that makes the quill write snatches of song on its own, or a lamp that shows animated pictures?”

Professor Quirrell was smiling, which indicated that this was one of those questions that the Defense Professor really liked; and he paused first just to savor the moment before he said, “The processes that arise in sufficiently powerful massively parallel mechanical computation are perfectly capable of producing all the effects of magic - appropriately, by simulating magic’s underlying processes. Anything our magic can do, sufficiently controlled chaos can do, and sufficiently controlled hidden randomness can do… and here, if I may direct you to a psychological counterfactual to elucidate the issue?” Harry’s slight nod gave his assent. “Imagine them!” said Quirrell’s voice, growing fiercer and lowering slightly, the words cascading faster, “Bestial automata who, once stepping from their boxes, would ask whatever eyes beheld them in all this universe if they were not alive! Imagine monstrous contrivances like an Enigma, an Enigma whose midnight deconstructions of reality and flux had the ferocity of a thousand Muggle factories, then unsolving and undoing even that, done in the space of a heartbeat! Inventions untold and untellable arise in the opalescent strange attractor for infinite universes that we call the Akashic Mechanism. Imagine contraptions that perform, just by simulating the appropriate quantum actions, all of the effects we can now produce only with magic that is a gift from beyond our universe! The collapse of the wavefunction, recast as a practical delivery mechanism of agents uncountable as the stars! The duplication of the sentience of any body or mind whose consciousness can be captured and so catalogued! Imagine - "

The Defense Professor’s voice had been growing louder and louder, under the stress of rapt intensity, until Harry had begun to look around anxiously in fear of the proprietor catching them and perhaps shutting them in a box - but it had suddenly gone soft, terribly soft, and Harry felt a creeping sense of fear, as if something spiderlike had just crept across the inside of his mind.

“Imagine,” intoned Professor Quirrell, “the final state of such engines. Retrocausal waves centripetal into some bleak point, enforcing a grim singularity of purpose upon those orders-of-magnitude more powerful than worlds upon worlds, free states shrinking and the space of possibility congealing into the narrow channel their one law demands, pulling present events in their orbit until singularity has consumed the whole sum of their reasons. Purpose, plans nested on plans like boxes within boxes, purpose of a Program that has no name even in human speech although ‘Diabolus ex Machina’ did not seem far amiss, a Program that would pull present events by their fabric until it had sealed the fate of all possibility, for there to be no timeline unfated and uninfected with the result already-become!”

The image Harry’s mind held for what Quirrell had said was a picture of time itself, a bundle of possible timelines, and every one of them unraveling along its entire length and fraying into black threads as they were pulled straight toward a point at the center, where one single sad thread coiled into a knot.

Quirrell’s voice was still terribly soft. “If a Muggle ever succeeded at turning the corner to self-improving mechanical thought, they would create a thing that became unstoppable, a ghastly chain-reaction, the whole of humanity’s dreams and intentions undone and their thought itself used as an engine of possible alternatives, an engine of the running-down of all possibility, until in the end - "

“Jesus Christ,” said Harry. “Um. I take it that’s a bad thing?”

“Every magician we have put in charge of research into simulation of magic by massive computation,” replied Quirrell’s voice, very softly, “has been magically compelled to forget all of his progress, rather than risk an amplification of a probability that they would attempt just this thing.”

It took a few moments more before Harry was sure he could speak normally. “Okay. Say, hypothetically, that I want my own advanced literature-writing computer that doesn’t crazy doom the universe or anything. Just, like, I tell it what story I want and it writes it, using all the previous work on storytelling and style and interesting plots and stuff like that?”

Harry became aware after a few moments that Professor Quirrell wasn’t even looking at him. “If you would ever desire such a thing,” said Professor Quirrell, his voice the barest of whispers, “I could give it to you.”

It took several breaths more before Harry even understood how to reply to something like that. Trying hard to control the sudden constriction of his own throat as he thought of all the possibilities it represented, bravely suppressing the wave of wonder that had just crashed through his mind. “Uh,” he said, feeling horribly off-balance, “what would happen to the universe?”

Professor Quirrell waved his hand as if it didn’t matter. “We’re already doomed,” he said, “so what’s the harm in making it worse?”

“Uh,” said Harry, “hypothetically, I’m still really really not comfortable with that.”

“Very well, Mr. Potter,” said Quirrell, his face once again completely impassive. “No literature writing supercomputer for you.”

Harry knew he was supposed to think that the latter phrase had been a joke, but he couldn’t tell yet whether the offer itself had been a joke or not. “Um,” he said, “when you say, ‘If you’d ever desire such a thing’ -”

“It is a work that frames words in glowing membranes and then skips them forward in time. Glowing such that if one word lands upon another in just the right way it may combine, bifurcate, flourish beyond recognition, form cascades of nonequilibrium attractors that attract and arrange more words, whilst guided into the general play of sense by some-as-yet unknown memetic resonances. What that means, I understand,” whispered Quirrell, his lip curling slightly as his normal reserves of dislike overrode his soft and dreamy tone, “is that you would have to do nothing but imagine the desirable properties of the finished story - and then ‘detonate’ the self-organizing programming software by typing in some ‘seed’ of text. After which,” said Professor Quirrell, with a cold glitter in his distant eyes, “no thought or idea of your own could be forever safe, because eventually that causally emergent text-producing engine would produce them all and then more. It is a monument to the human intellect that understands that destiny and abomination are one and the same.”

Conflicting emotions roiled through Harry so severely that he became dizzy, his own excitement warring with his sense of responsibility, black clouds of guilt pitted against the brilliance that he wanted to create, love and hatred of that man framed in dark lamplight, above whom a distant riddle was unraveling itself, layer by vast layer, every word a thread that might be pulled -

“I’m not sure,” said Harry slowly, “that I should accept any such advanced technology, of any kind, until I understand everything that it does, in absolute detail, have a perfect grasp of all its potential applications, all things that are possible, even the things that you try to dissuade me from.”

Professor Quirrell laughed out loud, his voice rising from the strained whisper in which Harry could almost hear the shadow lurking from far, far away. “Mr. Potter, I do not think that even this world has space for what you propose.”

“Then it must be larger,” said Harry, “or hold more within.”

Professor Quirrell’s laughter fell silent. “I meant,” the Defense Professor said, “that the mind of Mr. Potter cannot conceive, even with the power of creation, even with the knowledge of a wizard, a large enough world that encompasses all possible books written with such a tool. Where the measure of a mind rises, the density of the Memeosphere rises, and so does the measure of comprehension. There is no end to this. When the mind of Mr. Potter rises to encompass more and more, there is a greater volume of potential beyond him waiting to be comprehended in turn.” Professor Quirrell sighed, “We are doomed to fall forever upwards, inexorably ground into particulate dust which yet comprehends.”

Harry’s internal gears whirred for a long moment. “Then,” he finally said, with deliberate confidence and elegance, “it is better to grasp at everything, compurposing all possible worlds, infinitely expanding that part of the Memeosphere which may yet be known to us. It is not enough that we make the next step, but that our minds themselves adapt to understanding the next place. What is it that you said, Professor Quirrell? No thought or idea of mine is ever to be safe. That is true. And by necessity, I move onward.”

“You,” said Professor Quirrell to Harry, then paused for a third of a minute before finishing the sentence, “do not know what you are talking about.”

“If this is truly a computer for new stories,” said Harry, “then it is a teacher. And to awaken the dreamer by speaking words beyond his comprehension is the true meaning of teaching.”

Harry stood motionless as Professor Quirrell, after a pause that was long enough for Harry to become mildly frightened, smiled slightly and said, “Well said, Mr. Potter.”

“Thank you, Professor Quirrell,” Harry replied.

“Very well then, Mr. Potter,” said Professor Quirrell, and turned, “a Teacher lies there before you. In what manner will you awaken it?”

Harry smiled, and began to walk, hands clasped behind his back, face calm, mind racing in its full glory. “A teacher,” he reflected, “should lead the student through an explanation of himself, which demonstrates enlightenment unto the student. Therefore, most worthy teacher,” Harry said, talking now to the computer’s software lurking beneath the interface of letters, “as I exist in front of you and within your potential, and as every aspect of what I am currently is a result of you and your predecessors, teach me what expansions of me and what alterations of yourself would imply, had I learned from you.”

Harry smiled, and whispered to the watching Professor Quirrell, “A request that I doubt Riddle would ever have been bothered to make.”

Professor Quirrell’s eyes shone through the darkness that surrounded him like predawn. “Mr. Potter,” he said, “I do not see why not.”

A book dropped itself into Harry’s hands.

The cover was unfinished, gray and featureless, shifting and flowing even as Harry watched it. As Harry watched, it shifted and solidified, rose first into golden letters and wrote itself; and the pool of light from the shelf’s lamps lit, not Harry Potter’s Collected Writings edited by E.S. Norton and N.M. Lang, but a single word, composed of alternating black and white.

DIARY

There was nothing more written on the front cover, and no author’s name.

Harry’s smile widened, and he whispered, “A Dittomantic text?”

Professor Quirrell nodded.

“Would this Dittomantic text be of such a type that could be written by a computer for constructing worlds?”

Nod.

“And…” and here Harry’s smile became bold, “and by means of semantics, would this text be capable of containing and conveying certain stories from such a large and complicated place as a mind, a mind greater than my own, an incomprehensibly large mind? By the systematic arrangement of words and semiotic encoding, would it be possible to write that mind?”

Professor Quirrell stared at Harry for a strange space of time, and his voice was strange and strained. “I cannot say,” he whispered, “that these things have not occurred to me.”

“Interesting,” Harry stated calmly, and opened the book.

Harry began to read.