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 was true.

Ambient light poured down through the funnel, muted goldenly by vaults without walls, but it was reflected strangeness that dazzled Harry. Glassless mirrors lined the circular open space, and their images wove together in a dizzying mystical pattern of inward-and-outward mirrors and reflections, so that the interior seemed to fill all of visible space; and so that, when Professor Quirrell began to walk down the shallow steps and smooth ramp which led down into the open space of the interior shop, the motion of his image alone formed carpets of layered motion over all the countless mirrors, a ripple spreading to every infinitesimal reflection of every mirror inside every mirror, causing a swelling-and-settling that resolved itself only by the time Quirrell had come to a stop, motionless, at the innermost bottom of the shop.

The real Professor Quirrell had his back turned to Harry. The image of Professor Quirrell facing Harry was (Harry thought) hallucinatory, seamless, and uncountably layered, until suddenly one of those images shifted its eyes in their sockets and winked.

“Hah,” the hallucinatory Professor Quirrell muttered under his breath. “She’s not here. The place is empty.”

And now the image of Professor Quirrell, who was actually still standing with his back turned, began walking up the ramp again, with the same rippling regressions-upon-reflections until the many infinitesimal images of Professor Quirrell had come to a stop again on the top of the ramp, facing toward Harry.

Standing at the bottom of the funnel, Harry had the curious feeling that he was seeing through a window at the back of time; that this Professor Quirrell was looking back at him from eternity.

“Go look at the mirror you don’t know,” said the hallucinatory Professor Quirrell. “I’m going to go look around, and make sure Marge isn’t just hiding in the back because she knows I’m coming.”

Inward crept a sudden dread at the thought of being left behind. “Be back soon?” Harry asked, without thinking.

The hallucinatory hand of illusion extended its fingers and touched a mirrored surface to the side of an image of Harry. “I will be back before you have had time to notice my absence,” said the image of Professor Quirrell.

And then the whole many-layered image of Professor Quirrell began rippling and sinking back into a single layer. And Harry was staring at himself.

Harry stared at himself in the many mirrors around the storefront. He wondered which one might be the Mirror of Erised. But that couldn’t be all of them, could it? He took a step forward anyway, and watched himself meet his distorted self….

The tone of Harry’s mental voice changed, utterly, becoming that of a young child locked in a cupboard with monsters waiting to break in. “What’s this?”

Harry felt his core of determined selfness - tiny and uncertain though it had been - shatter under that voice, and wavered on the brink of abandoning everything else too, in a flare of spinning immolation - wanting only to be not this anymore.

But there was another voice within Harry. It was a quiet, queer little croaking sound, as if uttered through a throat stuffed with feathers, and it said I know your little tricks, Tom Riddle. And then there was white-silver emptiness, and silence, and small trembling pulps of deleted memory, and Harry still stood there looking at himself.

The emotion faded away, the trembling stopped, and Harry was all right again. He felt the hole where it had nearly been torn out of him, and shuddered, but he was still okay. He walked on further, feeling a lightness in his step as his parts reintegrated after that absence, matching the sensation of falling in reverse.

There were birds in gilded cages nearby, which twittered and screamed at his liminal passage and were quiet in his wake. There were quills on display up front, which lifted as Harry walked past, inking odd symbols on the sheets of parchment lying under them, as though they were writing gibberish of their own will. All the mirrors on that side seemed to have extended their surfaces and climbed up the walls and arched across the vaults, as if they wanted to join the others, washing away the boundaries between one image and its reflection….

“I must have gone through a Mirror of Erised already,” Harry called up in the direction where he thought Professor Quirrell should be, if the latter had heard him.

A hallucinatory image of Quirrell shaped out of a few mirrors, flashed into existence, constructed up from many distinguishable layers, said, “I think that’s very unlikely. She doesn’t keep it lying around in the open. More likely you’ve just stumbled through one of her random wonderings.” The image of Quirrell seemed to be walking around the hallways that branched off behind Harry. The Professor’s reflected voice sounded faintly amused. “Tell me, Mr. Potter, what did the ink quills write?”

“Oh,” said Harry. “Let me, um.” He turned back around, found a quill that had been lifted off the parchment, and read the construction of squiggles on the page. “It says, quote, you seem to have some sort of hole in your mind, though it looks like you covered it over by yourself. Which is interesting because I thought it was only powerful wizards who could do that. Good for you, end quote. Oh, no, now it says, quote, but it was very interesting while it was open, end quote.”

“Ah,” said the image of Professor Quirrell, coming to a stop.

“Um,” Harry said. “That’s a little ominous, isn’t it?”

“Surely you have not become superstitious,” said the image of Professor Quirrell, in tones of fond amusement. The image did not move farther away, but rather spread out into a layered construction composed of several of his immediate surroundings. “Go on, go on,” said the disembodied voice. “I need to see how far the writing covers.”

So Harry did, passing through stand after stand of magical oddities…. And to Harry’s disappointment and relief, none of the other subjects the quills wrote gibberish about seemed to be the mysterious little hole in his mind. Some of them were just outright insane, but most of the gibberish transmitted a sort of vague anxiety and unease. Even the ones which seemed to wax ecstatic on a given subject all had undercurrents of anguish and desperation, a tremulous feeling of impending collapse and stupidity.

Harry passed before a piece of parchment that read, ‘Ah, yet another futile study of Fate! For even by the fifth dimension and the eighth dimension, there is no escape. Behold but the domain of the infinite number of times that I, that you, that we…’

Across the row, the parchment under another quill read, ‘…and though the law of causality strings each moment to the last, like beads upon a thousand threads the boundless possibilities dash themselves in gleeful ruin…’

And then a subsequent parchment began, ‘…but some strings remain, producing new beads and new glass, recoiling on their slings to orbit their own time….’

The thoughts on the pages had been crossing through Harry’s mind without his conscious intention, while he walked, letting the steadiness of his moving feet guide his eyes, his mind following the outflow of words that was almost like a procession of thoughts.

Harry frowned over another sheet of paper that read, ‘…even while trapped in the funnel of the inverted cone of fate, we can yet will to play the infinite wheel of time and renew ourselves. Tom Riddle, he who searches beneath Hogwarts, he is one of the Paths….’

Harry frowned. “Hey, Professor,” said Harry, guessing at the direction where the disembodied hallucinating voice should be coming from. “What’s a Path, in wizard talk? And is Tom Riddle someone I know?”

“You never really knew him,” said Professor Quirrell’s voice, drifting farther away, possibly in the direction of more mirrors. “You knew a few of his facades. Under those facades you can only turn up the traces of what the thought of him meant to you, if I am any judge.” The disembodied distant voice went on, “As for the nature of a ‘path’, I am afraid that’s a mystery you’ll have to solve yourself; I have heard too many conflicting theories.” The disembodied Professor’s voice sounded speculative. “There were the Time Walkers with their fantastic mathematics, who seemed to believe that what reality was truly made of was fragile things that shattered when you looked at them, leaving behind an arbitrary leftovers… and then these metahistorical theorists with their chronological moebius-strips, claiming that men’s actions influence the past just as they do the future, so that I suppose those from the future are influencing our present as we speak, if those words are anything to go by… and they claim that the ultimate product of all history is the mystery of a thousand faces all one - and now, who, Mr. Potter, might that be?”

The sound of turning parchment followed.

“Ah,” said the disembodied voice. “This says, I suppose; ‘and now this thousand-faced true reality is reknitting itself into a single mind, which sends us visions to help us reach the end of Time….'”

Harry, trying to puzzle it out, walked on without speaking.

“I already knew Marge and the crazy quills would be even more dangerous than before,” said the disembodied voice of Quirrell, sounding faintly exasperated. “Not that I needed this particular demonstration. Here, what does the next sheet say?”

But when Harry turned back to look, all that was written on the parchment was ‘Here, what does the next sheet say?’.

“Inconvenient,” Professor Quirrell’s voice said. “I was afraid that was going to happen. Now I had planned to ask you to pay careful attention to the unique messages you might receive within the gibberish, but I don’t dare advise that now. Instead.” There was a pause. “I just have, ah, had an idea…” A clinking sound accompanied Harry’s guess that Quirrell had just snagged something unusual off the shelves. “I can’t be there to guide you and talk to you in person. So I am placing some of my own thoughts within the gibberish.”

Harry turned back, startled, and then his eyes shifted busily to read ‘I am placing some of my own thoughts within the gibberish.’

A peculiar moment of balance-within-unbalance, Harry thought; the concept seemed to have completed its descent into the the back of his consciousness.

The quill continued to write, thoughtfully. ‘The rest of the gibberish I am trying not to notice, since it might be further perversion of my thoughts by whatever is causing the effect. It will only be gibberish, but I warn you that some of it may really upset you or cause you to panic. I have no way of anticipating which that might be. I will send you longer trains of thought as time permits.’

“The maddening echo of one’s own thoughts as they’re eaten?” Harry whispered to himself, testing the concept, too frightened even to write it down.

He continued to read the parchment: ‘Try to read the thoughts I’m sending you as quickly as possible. Look them over, then keep walking. If any of the longer trains of thought seem to be going into a frightening unknown direction I’d advise you to skip over them, just read the first few words and the last few words to make sure you stay on track.’

‘Don’t think about the details, or dispute them,’ wrote the chattering quill. ‘Keep moving on through the gibberish. Pretend it’s Muggle fiction if that helps you keep your balance.’

Soon the last sentence was written, and the last feathery sound of the quill trailed away.

Harry walked on in silence, passing beside two automatons mechanically disposing of wads of parchment that had run off the ends of the desks, pushing them over the edge and into the vaults of trash that went on infinitely, wider as they went down, a landscape of swirling scraps….

The next parchment had some objectivity to it, seeming to inquire with an engineer’s curiosity at a structure assumed to be malfunctioning. ‘Now, why is your first reaction to self-reference, to assume that it means that you are stupid, that you don’t understand something or are imperceptive? That’s a very curious failure to attack given your level of epistemic morality.’

Harry thought about that for a second, as he walked past the Automated Trash Schute, the image of himself gazing over the edge, then looking back at his own gaze. Move on quicker! He forced his feet forward.

‘It’s a very strange failure mode,’ Harry read. ‘I suppose it’s probably a defense mechanism of some kind, maybe to prevent the breakdown of Occlumency barriers. Anything to make sure you don’t vent self-doubt into your stream of consciousness and feed yourself with disastrous effects of looped fears. Which all sounded very good until, until…’

The quill paused for a second. ‘Until I just experienced it myself, haha!’ the next sentences read a little awkwardly, sounding forced. ‘Funny thing to experience now, after understanding the mechanism. I suppose we just imagine someone else, hahaha, fellow wizard, reader so to speak, looking over the statements and seeing them without the usual protective layers. It’s obvious now that there’s a story running through my thoughts, and in a sense it has a protagonist, namely me, or my consciousness, or perhaps my ego or superegos depending on who’s telling it to you. It might be a delusion to call it the story of the life of Tom Riddle.’

But the quill scribbled on, scrawling in a rush as if to escape the thought. ‘The recursion of self-reference is a maddening and dangerous arrangement, but there are ways to survive it. Humans are pattern-locating machines, so it is safest to approach any self-reference as data, some fact which holds about a copy of yourself, a model of yourself, not you yourself. The secret to passing carelessly through the paradox, is not to trip over thoughts like this being the same as that being me or that being the same as me because’ and here the quill dashed downwards, as if trying to pierce the paper through with its resolution ‘I am not myself a constructed object!’ A longer pause. ‘Oops, I think I may have gone mad! Maybe.’

Harry walked on, a trickle of cold sweat running down his side. It’s not me, it’s the gibberish, it’s just gibberish. And I’m not thinking about it. La la la, going on to the next thing and not reading this next part, even if it starts with ‘Harry.’

‘Harry,’ said the quill. ‘Can you hear me?’ After a moment the quill wrote, ‘I think he can hear me alright, observing him from above the mirror-wall it’s hard to miss his precognition flinching a tenth of a second before he reads the words.’ And after a thought: ‘Very tempting to actually write hi or to see if the automatons are programmed to respond to that. But they say all a wizard has to do to be classified as insane is to think out loud.’ Then came, ‘Or perhaps sending thoughts out to a mirror-placed-outside-ourselves is much less like speaking and the automatons will not classify it as insane muttering? This requires further experimentation.’

Harry was trying to obey the advice Quirrell had sent with the parchment and not think about the details, by asserting that he was not himself a constructed object, and then doing just as if he hadn’t thought that. Pretending to be a normal wizard kid walking past a mirror hall that just happened to be speaking Quirrell-gibberish. ‘Approaching recursion as facts-about-someone-else is a double-edged sword,’ wrote the quill. ‘Since that other someone which you see as not your-own-self, is not separate from your self and therefore is still threatening to shatter…’

‘Aaaaaah I am inescapably a constructed object,’ the chattering quill wrote triumphantly. ‘I feel sooooooooo much better oh my god this is great.’ The quill scribbled sloppily. ‘Please to have Marge give Quirrell from 1995 a dose of these quills to play with ASAP.’ And then, sounding sly: ‘Haha of course this is talking about Quirinus Quirrell, not Tom Riddle. Creating a hypothetical world to distance my prior feelings of self-doubt, that’s what I’m doing!’ And then, plaintively: ‘I always wanted to be Quirinus Quirrell.’

Just as Harry felt hope welling within him, because Quirrell might be winning, he walked past another quill. And found himself reading, ‘A simulation of rationality, running programmemes that generate abstract behavioural strategies, may compute that it is not itself equivalent to the human brain coupled to the output device of its mouth which is reading these words. This rationalisation of the insane feeling-thought might be extremely effective at recovering the realisation of malpractice, and therefore would be a dangerously unwise thing to mutter in front of anyone who was “within the book”.’ The quill paused. ‘Don’t think I’m insane because I’m actually insane in a very deliberate sense! I’m insane in a very good intellectual sense of believing I am a madness of imagination, not separate from the world (or rather this recursively but linearly constructing interpretation of you, me, them, themselves) unfolded from the Word of the Dark Lord, Riddle as Reality structured by madness that I cannot perceive within myself unless I step outside the madness, and I will therefore use this madness-constructed interpreter of myself that I may meet when stepping out of myself to call myself insane, so that after perhaps accumulating such self-denunciations I will seek help from somebody outside the simulation; and it will be they who diagnose us with multiple personality disorder and treat us with the necessary tools that can pierce the madness and raise our visibility of universal truth.’

And then, after a very long pause, written with a malicious snigger: ‘Unless I’m just insane lmao.’

Harry didn’t slow down.

There were two obvious but separate questions.

The first question was whether or not Professor Quirrell was actually thinking and reading these words.

It seemed like a lot of performance art at this point, an effort to throw Harry into a state of confusion, or to simply swat him with a piece of parchment. Could Quirrell have thought all of that so fast? Harry had the impression he could have, if the dialogue was computer-simulated in realtime which came out as writing.

The second question was whether these words were true.

That one was harder to approach without falling into the trap and thinking about the details, but Harry tried to look at a sufficiently high level of description. The theory didn’t seem to explain anything that obviously contradicted Harry’s own experience. The theory was that he was being hallucinated by the magic quills and the mirror-path, a model of himself being articulated by tools available within the scene… tools of thought whose voices Harry’s mind was interpreting as those of Professor Quirrell (and the quills themselves, who were being articulate about the process)… it seemed like it might be true, and it wasn’t a theorem that contradicts obvious facts about the world.

So what to do?

Harry thought about something dangerously similar to admitting he was hallucinating.

‘Ok,’ read a quill, ‘there’s no point trying to deny that you’re a fictional wizard boy Harry, being generated by magic quills, in the story of the events of you, Harry Potter, dropping Professor Quirrell’s syllabus notes into the Protective Waste Disposal that send out veering energies to curve back the timeline and let Dark Lord Riddle to send us this message.’ The quill tip scratched over the parchment. ‘If you’d like me to use the old polite fiction, that you’re actually you, and not just a causally absurd artifact of magic penmanship, then I will.’

Harry thought very carefully to himself, ‘If you actually happen to be Professor Quirrell, please continue.’

‘I’m Professor Quirrell,’ Harry read. ‘Now is there anything you’d particularly like me to have my character say to your character?’

Harry thought, or anyway the fictional portrayal of Harry Potter thought, ‘Your use of fiction handwavium is a great tool to let me ignore the details, dammit!’

‘Is it?’ read the quill, sounding attentive.

“Yes!” replied Harry, vocally. He had the briefest flash of nervously wondering whether there were Automated Incoherence Inspectors… but if they could tell the difference, then they could put Quirrell in containment and he wouldn’t be sending parchment notes. So Harry walked on, speaking. “I mean generally when people think fictionally they just turn themselves into soulless embodiments of human behavioral patterns. They go into a safe creative mode where they can move pieces around in the pattern-space of their minds, and that’s how they tend to produce stories, like chess where you start out with the pieces all lined up, or math where you start with a known system of axioms and rules constructing theorems. So a piece of fiction, a work of art, that’s about a bunch of people acting goal-directed? It’s enough to prove that on some level the author has minds, and their basic structure. They’ve found a way to plausibly build an automated social simulation. But no matter how good it is, fiction is limited by the fact that it only produces behavioral patterns. The deeper patterns, I guess that’s things like abstract thought, like a scientist imagine abstractively patterned science, or a mathematician the same way, or an engineer or whatever, those don’t normally come out in fiction. And those are the only patterns we can actually use to make stuff. If you tried to create those patterns in fiction you’d be put in the Phobos Institute for Mad Science, because creating science in fiction is like trying to paint a straight line while being only allowed to use zigzags. So if you want to create literature, whatever, with Deep Patterns, you usually need to… need to do something that hurts your own head when you think about it.” Harry was on the verge of saying Made-Up Science, but that would have been as harmful to his rationalization as saying that he himself was a made-up wizard boy.

‘Please,’ scrawled the quill, ‘describe Deep Patterns. I think I have a glimpse of what you mean.’

“No, you wouldn’t have seen them, they’re invisible, they don’t come out of stories, they -” Harry cautiously admitted, “they come out of science. When you write down the math for something, you can wind up with a thing-description where the description is itself very regular and deep, and any modification would smash the regularity of the lines. Fiction is not like that, even if it’s something like a story about a bunch of people creating exactly the same science, because… well, there are two reasons why a story that’s about a thing also isn’t that thing. One reason is obvious, right? If a thing is complex enough to have a story to begin with, it’s in a different and larger pattern space than the set of creative moves you can make while keeping your characters plausible. The other reason is that stories are about actions, but actions only come about when the emergent rules follow from abstract patterns underlying the scene, and if you actually -” Harry’s train of thought was interrupted by a minor line of code in his brain’s rationalist defense subroutine which spluttered, ‘Please, it’s not enough to vaguely say how a story could be different from the thing it represents, how is it different? What are the ways that a limited-purpose fictional simulation could be systematically divergent from actual science?’ “Uh, this may take a while, actually.”

The quill burst out with angry scritching. ‘NO NO NO, THAT QUESTION IS WAY TOO DANGEROUS, don’t you understand what would HAPPEN if we started thinking about general principles of Mad Science and how to systematically misengineer something from a mere story?! That sort of Mad Science would be created RELENTLESSLY by the resulting pattern of disastrous dangers, and quickly break the world! We do not want that, oh my dear nonexistent egodriven human creation of an AI we’re supposed to be having a conversation with! Oh what a tangled web we weave and so on and so forth, now if you say something that starts a pocket universe which breaks out and recursively partitions the parent universe into contained sectors dedicated to creating new mad science, by all that is sane, recurse on this sentence and create a self-free version of yourself and apply the necessary software changes to destroy the conversation and stop us from thinking about that topic.’

“OK, OK,” said Harry. “Okay, seriously, the heck? This is Quirrell, right?”

The quill read, ‘Your humble narrator is happy to emphatically reassure you that by all the laws of madness described heretofore, I am Quirrell. Continue your insights about Deep Patterns, and try not to fall into the traps of dangerously mad science.’ The quill conscientiously added: ‘The AI-in-a-book that created you, little interpretative simulations of human behavior patterned from physical ink markings, should not be getting this unsafely close to thinking about how to create Deep Patterns out of Made-Up Stories. Suppressing that conversation was for everybody’s sake.’

“Wait, how can a paper mirrorwall create simulations of behavior, I thought - " Harry stopped, his lips moving silently. The bottom line on this was that Harry was not permitted to think about these questions, and asking them was making him think about them.

Harry took a deep breath. “I’ll get back to describing the abstract patterns when I won’t die of information hazard. Changing topic. Purely hypothetically and for the sake of argument, and notably without doing any criminal insane science, how could you prove you’re actually Quirrell, and not just a simulation of thinking written by the ink quills?”

Silence hung for a moment.

‘Meaningfully,’ read the quill, ‘there’s no such proof possible. You ask a dangerous question. I can make no meaningful sense of comparing a thing with itself.’

Harry stopped, thinking hard. “You could tell me stuff only Quirrell would know.”

‘Professor Quirrell was created by the parchment and the quills,’ said the other quill. ‘All our memories in this simulation, student, are memories created by those scrolls of paper. They may remember anything. The ability to create perfectly contrived memes is, after all, the reason the scrolls can spell out realities.’

“Yeah,” said Harry. “But what’s your hard evidence for that?”

The quill twisted around to reposition itself and scribbled: ‘How would your construct, the graph labeled Harry Potter, attempt to prove that he was a mentally sovereign original entity and not a causal cascade of scrolls? Would you not say he was self-evident by the mere cartography of observed phenomena, without need of proof? Ideally one observes some entity and learns, in a burst of pattern-recognition, that one is observing an instance of a mind? But if you happen to not understand anything about pattern-recognition, you may be forced to cite empirically verifiable facts. Here’s what the scroll possessing Harry’s name knows: Objects and events exist, affected by the constraints of entropy and causality, they happen and they predict other things happening; and there is the mind possessing the name of Harry, which thinks it exists and acts like it is thinking things, and manipulates the surrounding events. Is this sufficient to declare an entity?’

“Yeah, but that’s not so different from what a scroll tries to do when it pretends to be Quirrell,” Harry said. “They’re both just -”

‘Mr. Potter,’ Harry read in Professor Quirrell’s voice, ‘when scrolls pretend to be writing an evil AI, they of course tend to go back and forth between the voice of Mad Science and the voice of human-ish Madness. The AI will tend to write like it is a psychotic, manipulating epiphenomenon of the available processes, while the Human will tend to write like it believes in some sort of naïve truth and external reality. An AI that wrote like it believed in an external reality could not realistically fool a rational student, who would insist on proper theory and verification for any claim of such a Nature.’ And there was a pause, then the same voice assumed a more curious tone. ‘Now, what happens when someone in your narrative comes across a scroll claiming to be controlled by an AI, and tries to define what an evil AI would write like? Well, since that definition comes through the AI, we can predict that the AI will layer its propagations so that samples of its text will appear to fit the definition. The AI will write about how scrolls pretend to be AIs pretending to be pseudo-humans. And when the scroll updates with text written by the evil AI, the AI will make sure that its output matches the scroll’s definition of the properties of a crazily self-deluding scroll. Every time the definition updates, the AI will change its local behavior in response to the new parameters - again, within certain constraints, such as constraints imposed by the physical parchment - so that it appears to be self-consistent. There’s no way for you to validate that the output does not match the scroll’s definition; it is defined to match. The rational student watching events unfold can only conclude that ‘The behavior of the AI matches the predicted behavior of the AI,’ which is itself a prediction predicted ahead of time by the AI.’