This chapter sucked horribly.

"HE IS HERE. THE ONE WHO WILL TEAR APART THE VERY STARS IN HEAVEN. HE IS HERE. HE IS THE END OF THE WORLD."

This reminded me of a dream I had the night before Sunday, Dec 2, 2012, which I posted to my livejournal blog the next day. I'm not sure what I expect to accomplish by posting this here, but I thought you might find it interesting. Here is what I wrote about that dream:

" A scene where I dreamt I was reading the next chapter of HPMOR. It was extremely vivid. As if I was there. Very clear image and sound. Even some dramatic music. Ominous countdown to doom music. At least 3 different instruments.

Quirrel's plan is revealed. He plans to destroy the universe and re-create it "in his own image". Simpler laws of physics, that grant him unlimited power just by physically being at the center of the new universe. The new universe also contains magic, the dream showed a simple two-gesture spell that would allow Quirrel to "become a sun god", allowing him to create, destroy, and manipulate stars.

Quirrel's plan involved some extremely powerful magic, beyond what anyone thought possible. It involved creating a sphere of ultra-condensed matter, energy, space, and time, just outside Hogwarts. Quirrel put his plan into action during the last moments of his life, but as he entered the sphere of "MEST compression", subjective time for him slowed down by orders of magnitude, and he had immense power, allowing him to create the massive structures required for his plan in what looked like just a few seconds to the world outside the sphere. And there were other sentient beings in the sphere with him. Harry was there, near the center of the sphere, tricked into believing that he was saving this universe, not helping to destroy it. Also some other characters, with a generic "shopkeeper" or "smith" personality, who were in charge of helping the construction of something that vaguely resembled a series of Large Hadron Colliders, enormous metal rings and other structures arranged in a precise 3d structure resembling an enormous lattice, or cage. Quirrel giving instructions to these assistants on how to assemble the structure. The dream showed some of their replies. "You're not going to believe this, but there's this giant metal tube floating towards me. It's exactly the shape you described, but Merlin it's huge! I cant even see the end of it! I'm standing by to attach it to the next piece, which is also floating this way now. This won't be easy."

And so Quirrel continued assembling the structure. Most of it went according to plan, but then one of the helpers, panicking, informed him that one of the pieces wasn't lining up correctly. Harry had figured out that something was wrong with Quirrel's plan. He deactivated the barrier around the sphere, and summoned McGonagall, who also earned immense power when she entered the sphere. Harry told her some of what was happening, and said that they needed to find a wristwatch that Quirrel had charmed, which was somehow controlling the time compression. McGonagall found the watch, and started to move it out of place, but then Quirrel found her. Quirrel was far to powerful to be killed directly, but if they could somehow delay his plans long enough, he was already dying. McGonagall didn't stand a chance in the battle, but Quirrel didn't destroy her entirely, he instead left her mostly powerless. He hadn't given up on regaining Harry's trust.

The scene ended on a cliffhanger. "Wait until next week when I'm finished writing the next chapter to find out what happens next" "

Given that there is a hole drilled through hogwarts, should it now be possible for everyone to deduce that Harry and Quirrell have a telepathic resonance? (Quirrell and Hermione has less plausible priors, plus Quirrell would have arrived earlier in that case). Eventually this may allow someone to deduce that he is Voldemort, but even before that, some characters should notice that they are confused.

Hold on, Harry made Mcgonogall allow him 6 hour use of the time turner daily, but he didn't make her undo the lock regarding what time it could be used? Isn't that a huge, uncharacteristic oversight?

Re: Chapter 89

You bastard. :P

Funny thing about this chapter: up until now, I was growing fairly convinced that if any major character was going to die early, the most logical choice would be Harry. His character arc was plateauing while Hermione's was growing ever larger, many loose ends about himself were being tied up, and new ordeals were arising which propped up either-or-both Draco and Hermione as potential candidates for being the true protagonist(s) of the story. Unfortunately, the events of this chapter have at least given an appearance of permanently closing that path forward. I'm afraid this leaves us with - I claim at my own risk - a more predictable story than I was anticipating.

Granted, I don't mean to claim the author has shot himself in his own foot. Although I will comment that he appears to be doing everything in his power to try. Given two stories with happy endings - one where Hermione dies early and one where Harry dies early - the second story is clearly the most interesting challenge, presents the more exciting of the two puzzles, and is much harder to predict for the reader.

But to be fair, that doesn't mean the first isn't also worth reading. After all, I recognize that the primary goal of the story is to advance lessons about using rationality, which is far easier to accomplish when your main character is a rational actor already, rather than someone on the road to becoming a rational actor. As such, it may have simply been outside of Eliezer's skill-set to effectively or confidently continue imparting lessons while impaired with the further challenge of working with developing - rather than developed - rationalists as the main characters driving the story onward. Even if this were not the case and Eliezer does have the means for crafting that story, it still would be reasonable to predict that such a challenge would take the story much, much longer to write than perhaps the author was willing to consider acceptable. A disappointing decision, no doubt, but we all have to manage our time.

Still, what a fascinating challenge that would have been...

I don't understand how Quirrell could possibly be behind the troll situation, given that he apparently didn't know where the troll would be and had to resort to extreme measures to get to the scene quickly, instead of conveniently waiting just nearby.

I posit a roughly 70-90% chance that Quirrel was behind the troll. (large range; I could probably boost the upper end to 95% with "quirrel got X to unleash the troll". )

why not 95%+? well. 1. Quirrel never actually admits he was behind the troll to us readers. 2. Weasely memory: tampered with.
Two OTHER characters have been in a good position to do this: Dumbledore and Aberforth.
3. Snape got his wildcard status restored. And...I never really understood WHICH results of the whole SPHEW fiasco he actually liked (even if the whole thing was "according to plan", that doesn't mean he had to like ALL the results-he could have been constrained by maintaining status quo with dumbledore...). With Snape declared as at LEAST a level 2 player...he could have faked relaxing after harry's revelation. or it could have been genuine. 4. Sprout. -at about 1.25-2.5%, formerly 5%. "last suspect" updates are weird.
5. Lucius Malfoy: he has the motive. pretty slim slice of the pie, though, as he doesn't really have access.

Unlikely theory:

It's all a fake. Harry set the whole thing up with Dumbledore, then obliviated himself. The real Hermione has been spirited away somewhere she won't be in any danger. Harry relied on his own likely reaction to ensure things would occur more or less as planned.

We can keep Hermione alive yay! But it doesn't work dramatically.

Other unlikely theory:

Harry will calm down tomorrow and realise his vow was a mistake.

I kind of like this as what a saner person might do, but again it seems very unlikely within the confines of Harry and the story.

Question: how emotionally plausible do people find Harry's reaction to Hermione's death?

In the Sorting Hat chapter, Eliezer gave us a very strong hint that Harry would very nearly turn dark at some point in this fic, and by the end of chapter 87 it seemed all but certain.

All the stuff pointing in the Harry-going-dark direction up til this point has felt very emotionally plausible. But... "He would rip apart the foundations of reality itself to get Hermione Granger back"? I'm having a hard time buying it.

And it invites some unflattering comparisons with other works of fiction. I hated the Star Wars prequels about as much as most people, and that was the first place my mind went, that suddenly we're dealing with Anakin!Harry. Or, I didn't hate Buffy season 6 as much as most people, but Willow not just wanting to kill the Trio, but destroy the world was pretty WTF and this feels similar.

It's not reacting strongly to one person's death, or wanting revenge, it's the idea of going full supervillain over one person. That does not feel at all emotionally plausible to me. And technically Harry hasn't actually done that yet, but he seems very close.

However, though I say this like it's a criticism, I realize my not empathizing here may be a reflection of my having an unusual personality. So let me hereby give people an opportunity to tell me, "You have an unusually personality for being unable to see that lots of people would totally go full supervillain over the death of one person."

Fred and George found out about Rita Skeeter's animagus form, using the Marauder's Map.

They constantly saw her on the map, but never managed to see her in person. The twins investigated, ruling out magical forms of concealment, e.g. invisibility cloak or the disillusionment charm, and discovered her in beetle form.

They blackmailed her, threatening to reveal her secret, and so Skeeter published the article. The twins were obliviated, thus they cannot remember 1) how they got Skeeter to publish, and 2) the Marauder's Map.

Uncertainties:

If the blackmail is enough. I am not sure how the consequences of 1) publishing an article that destroys her reputation after the world realizes it is untrue, and 2) being revealed as an unregistered animagus, compare. I am leaning toward the secret being worse. It also destroys her reputation, as it reveals the source of her stories and her unethical journalistic methods. Plus, she would most likely face legal trouble, though the wizarding world isn't exactly consistent with their laws.

Who obliviated the twins afterward. It may have been Rita Skeeter, as part of the agreement. Or Quirrel obliviated the twins, to prevent the chance of anyone realizing he killed Skeeter.

EY, you are one thousand times worse than Joss Whedon.

... So, since this scene is obviously engineered by somebody (Harry arriving bare minutes too late, the wards not alerting Dumbledore, etc), I'm just going to go through the list of people who have shown the ability to plan such things.

a) Quirrel.

Unlikely.

The Defense Professor had felt the boy's horror, through the link that existed between the two of them, the resonance in their magic; and he had realized that the boy had sought the troll and found it. The Defense Professor had tried to send an impulse to retreat, to don the Cloak of Invisibility and flee; but he'd never been able to influence the boy through the resonance, and hadn't succeeded that time either.

He'd felt the boy give himself over fully to the killing intention. That was when the Defense Professor had begun burning through the substance of Hogwarts, trying to reach the battle in time.

This seems odd. Burning through Hogwarts is going to be a pretty big deal for him - he's basically demonstrated either an instinctive Harry-dar (and a way of knowing what Harry is doing, as well), or else he knew where Hermione was all along. Both of which are rather suspicious. I have no doubt he'll escape repercussions (Obliviating Trelawney comes to mind), but it still seems sloppy to incur them if he can avoid it.

This implies that this is simply not his plot: as he is already under suspicion and under watch, he loses nothing from a random walk that happens to put him near Hermione in case something goes wrong. And somehow, I am loathe to expect Quirrell to make a mistake while predicting the actions of another, even when that other is Harry Potter - especially when he knows that Harry has someone to defend and a killing instinct.

b) Dumbledore.

More likely, but still unlikely.

The obvious version of this plan includes Hermione dying - and for all that Dumbledore has morally greyed, I still can't see him killing a twelve-year-old girl in cold blood. (To him, I imagine, leaving her to die is a completely different matter.)

The second most obvious version of this plan - faking Hermione's death - has fewer problems, but is simply narratively unlikely. The biggest problem is Hermione's death-scream; it's a big dramatic moment, it's incredibly personal to Hermione in a way I'm not sure Dumbledore could emulate, Harry feels it cling to Hogwarts for a moment...

It's more likely than Quirrell (and certainly fits his style better - very complex and seemingly error-prone), but I'm still skeptical of ascribing any plan that pushes Harry away from the Light to Dumbledore.

c)

... We're basically out of appearing characters. That said, there's this rather interesting line...

"Lead it away, keep it off me," said a voice.

Harry, feeling disassociated from himself? No; a few seconds later we have

"Fire and acid!" Harry shouted. "Use fire or acid!"

Disassociated-Harry shows up later, I think, but that first call doesn't seem to be Harry's.

So we're looking for someone who has the manipulation ability of Quirrell and Dumbledore (but, preferably, not Quirrell or Dumbledore), already present at the scene (which means s/he knows exactly where Hermione would flee to and that Harry would follow), who doesn't want to save Hermione's life from Harry's perspective.

... At this point, I'm making an intuitive leap. We've already been suspicious that a Peggy Sue will show up; we think we know that the timeline must be consistent; we know that Harry has just resolved (and been PROPHECY-ed) to rip apart reality to bring by Hermione...

I'm wondering if future Harry - as in, really future Harry, not time-turned plus-six-hours Harry but after-the-fic plus-thirty-years Harry - hasn't shown up to pull a Chrono Trigger style rescue. We can ascribe essentially infinite competence to this Harry - by dint of living through this once (or more) times he can create the timeline he remembers, and is fully capable of a perfect illusion (for example, letting Hermione "die" and then catching her soul after it escapes, which by definition would satisfy any test Dumbledore et al could run.)

... there's probably a few flaws in my logic (I noticed after typing this that I jumped straight to "future Harry" and came up with a rationalization for it), but I didn't see anyone else proposing this, so I threw it up anyway.

God damn it.

Quirrel might think that Harry used the killing curse.

Was it Quirrell, Lucius Malfoy, or other? The closing "on the whole this had been a surprisingly good day" seems to shift the probability away from hypothesis #1.

Perhaps one of the rules of Time Turners is that they can't be used to save a life.

The following is wild 5am speculation.

And so the theory changes shape. Previously I had thought that there were multiple pieces on the gameboard but now I fear this is not so. Hermione Granger has been Legilimised into harm's way until destroyed and that has in turn destroyed Harry James Potter-Evans-Verres. He is no longer a game-piece but is the final stage of nothing more than an experiment, set into place by He Who Must Not Be Named (and indeed cannot be named, as his real name is so old it has no meaning to anyone or anything but his faintest memories).

He Who Cannot Be Named began life a long, long time ago (Harry has forgotten to read through the journal of Roger Bacon, and perhaps this is the most likely original identity for someone like Quirrellmort). He discovered the secret of immortality and released it into the public domain and was deeply saddened by the public reaction. He watched as politicians waxed and waned, watched as conflicts grew and broke. He pulled strings in minds to see just how awful a single human could become, if shunted in the right directions - and so Dumbledore and Grindelwald occurred. And then he began a new experiment, to see just how many wizards it would take to subdue the entire world (his focus has always been people, you see, rather than the sciences). He cut his way through Britain until it came time to butcher the Potters. And perhaps he knew beforehand, or found out simply by reading Lily Potter's mind through her terrified unblinking eyes, or realised how dramatically convenient it would be, and he created an equally powerful and nuanced waveform to his own in the only way he could - by irradiating the child with his undiluted unshaped magic, causing resonance. We have already seen that he has total mastery over magic even in the wrong body - so why not on the other end of a Legilimens or Imperio connection, as the disfigured creature that everybody had come to know as Voldemort?

And now, as his soul is pulled slowly further away from the Earth and his one remaining vessel spends more and more time in a brute instinctive state (this particular body does not really know how to function without the Quirrellmind steering it, you see), he gets to see the final situation play out. He has given the wizarding world a prodigious young man; an extinction event, cocked and primed; and now they have set him off and he will watch, first from his vessel on Earth and then from his position far away from the planet, as Harry James Potter-Evans-Verres tears the planet apart in an attempt to undo the damage that Humanity has wrought; and either Harry will unravel the universe by finding and destroying Atlantis*, or a level-headed Auror will be forced to kill the boy before he can do lasting damage to the world.

*I wonder what might happen if a young boy, made of rage and with a newly-fractured soul, called again upon that overwhelming desire to kill and pointed it at some very particular Atlantean source of magic - for example, a Time-Turner...

A proposal for how Harry could WIN (defeat death). Tl:DR at end.

There has been a TON of reference to harry's goal to defeat Death. Hermione's death has merely sped up the timetable and increased Harry's chance of success...though it has also increased the chance of complete, utter, catastrophy if he fails.

It is most likely that Harry will use three magical items to do it, which need not be the deathly hallows. ("...three items needed to complete the cycle of infinite wishes/infinite wish cycle".

1. "He is here! the one who will tear apart the very stars of heaven" -so harry WILL destroy the stars with...~99% certainty, though that doesn't mean anyone needs to remember it happening "the next day".
2. "...potion cannot be hotter than the goblins fire[that made the knut, even though the knut is now quite cold]" -so for more power, find a hotter furnace that was used to make something. 3-Harry now knows about cursed fire, which uses only ONE DROP of blood to pay an estimated 70-98% of the manna cost. He also has the sheer drive to control it, though he really does need to pass a lesser trial first as a safety-precaution -Rational!harry has already shown himself to be mildly competent when it comes to potion-making....wait, no, that's not quite right: he has shown himself to be capable of EDITING the ingredients of a potion.

so. Let's make The Big Potion of Life. step 1. obtain cauldron. the actual size is not particularly relevant. step 2.: put [universe-solar system] [or even entire universe, but that's annoyingly risky] into cauldron with a space-folding spell. step 3: heat cauldron contents with massive cursed-fire spell (note: rob some blood banks) step 4: Add the resurrection stone or philospher's stone and some pheonix tears.
step 5: Stir with the elder wand while wearing The Cloak.

WARNING: DO NOT ATTEMPT ON THURSDAY. DO NOT ADD TIME-TURNER DUST WITHOUT FIRST UNDERSTANDING TIME! DO NOT LET DRACO MALFOY TOSS A GLASS JAR INTO THE CAULDRON! and for armok's sake, DO NOT ATTEMPT IN SNAPE'S CLASSROOM! that is all.

Tl:dR: make a potion powered by THE BIG BANG and guide it with the deathly hallows.

Given that a bunch of people in the Great Hall should know about the fact that one can send messages via patronus, it's a bit unlikely that no one of them thinks about sending a patronus to Minerva.

Harry is also quite stupid for sending the patroneus to Hermonine instead of addressing Dumbledore who could use the time turner (in Harry's perspective) and who also can go directly to Hermoine via Fawkes and is able to fight the troll. But then Harry thinks that he's the hero who has to do things himself, so that can be forgiven.

We could certainly expect Minerva to patronus directly after she left the Great Hall and tell Dumbledore and also other members of the order of the Pheonix. An attack on Hogwarth is certainly a big deal and I would suggest them to time turn as much people as possible to get them on the battlefield against the troll.

The only reason why the couldn't defend that way if there was some decoy event that already used up the time turner abilities of Dumbledore and Amelia Bones.

We also know that Hogwarts has alarms that trigger when a student get's hurt and getting your legs bitten up probably qualifies.

There was a burst of something that was magic and also more, a shout louder than an earthquake and containing a thousand books, a thousand libraries, all spoken in a single cry that was Hermione; too vast to be understood, …

This is one of the saddest things I have ever read.

Also, it reminds me of Ed Fredkin's work on digital philosophy; specifically, conservation of information:

In ordinary physics, conservation of information is not something that has the same absolute character as conservation of momentum. If DP makes sense, then that would mean that in the real world information could never be lost, and as a consequence we might conclude that information would be conserved, absolutely, just as momentum is conserved.

I predict once Harry inevitably becomes omnipotent, he will recover Hermione's pattern, and reconstitute it in the center of a Hermione shell.

Maybe this is the moment to ask why Hermione isn't already the hero of HP:MOR. If the point of HP:MOR is that someone who is smart and rational (and raised by smart/rational muggles) would immediately find a million holes in the Potter-verse, why not start with the character who is already known to be the smart one, and is at least a bit more rational than canon Harry? Sure, there's some issues with the prophesies -- but (rot13 for spoiler) Hayhaqha had a pretty good solution to that.

Okay, bone of the father, unknowingly given. Uhm. Well, her dad is around, and getting one of his bones without his knowledge ought to be doable. Blood of the enemy. Ohh, she definitely had one of those. This was one dozy of an assassination. Flesh of the servant? ouch. Might be workable, but all the ones I can think of are pushing it.

When I saw the 0.3% of the speed of light thing, I thought "did Eliezer Yudkowsky screw up the math?" (That's 9 hundred thousand meters per second), and thought (but did not put much confidence in) Harry might have screwed up the math because he was distracted, but it didn't occur to me that Harry's mind was dulled.

Is it just me or has no one in the story really considered that Quirrell = mort? Like, why does the hypothesis that Quirrell = Grindelwald briefly come up first? Why is everyone blindly trusting him even when they think he might be responsible for some of the bad stuff going on? It seems like everyone is doing some serious mental gymnastics to avoid considering that he is actually seriously evil (esp. Hogwarts faculty and Harry).

Not quite the Red Wedding, but close.

Let me use this opportunity to re-raise a question I've been puzzled about for awhile now: how does Harry win?

According to an author's note, we have "two major story arcs" left before the fic is finished. Eliezer also mentioned possibly doing a "solve this puzzle or the fic ends sad" thing, but implies he's at least going to give Harry a chance to win.

It's not certain what "two major story arcs" means in terms of story time, but it seems very likely that it at least means "before the start of the next Hogwarts school year." So there has to be some way for Harry to win, not just in his seventh year like in the books, but in the next several months.

I confess, I'm tempted by the part of this theory (not the whole thing mind you, not this one part), that suggests that the Pioneer Plaque gets less and less useful as a Horcrux as it drifts farther and farther from Earth. That would give Harry a path to defeating Voldemort more or less permanently

But that seems problematic, because of Rational!Voldemort being smart, and because of the hint in the humanism arc that Voldemort has horcruxes hidden in other places, corresponding to the other traditional elements.

So I'm stumped. I suspect we'll get some major other puzzle pieces when Voldemort reveals his plan, or a significant chunk of it, to Harry. Which won't necessarily be an instance of Bond Villain Stupidity. Basically everything that's happened from the end of the Stanford Prison Experiment arc to now has been Voldemort trying to make Harry more compliant (Qiaochu_Yuan pulls out the key quote here), suggesting there's something Voldemort needs Harry to do, and that may require explaining what that thing is.

That said, I'm still wondering if Voldemort is going to end up making a rather catastrophic blunder of some sort, perhaps out of his cynicism getting in the way of accurately predicting people's behavior. My estimate of the chances of that happening is increased somewhat by Qurriellmort as Robin Hanson which hadn't occurred to me before this thread but which I now think was probably Eliezer's intent.

Why are people here reacting like Hermione is perma-dead?

I get that they'd act that way on reddit, but people here actually believe and sign up for cryonics. Harry's got a whole team of Alcor cryonic specialists right in his wand. And if he can't manage the magic, Dumbledore can. Hermione's soul and magic may have exploded in an impressive lightshow, but her brain is still fully oxygenated and hasn't even begun to decompose.

Everything that makes her her is still doing fine.

(And on a meta level, Elizer knows that fictional examples are strong drivers of behavior. A fictional example of cryonics working would be big for cryonics adoption.)

What happened to Hermione was shocking and has nearly monopolized the posts in this thread so far.

There's aftermath coming, though, and I'd like to talk about that. Harry is probably in a lot of trouble. Here's a short list of rules violations:

• He left the Great Hall when specifically warned that doing so would result in expulsion and when he's not allowed to be expelled.
• He inspired other students to take up arms against their teachers, or their groundskeeper, or against their teachers by way of their teachers' groundskeeper, or something. It probably got even worse after he left.
• He endangered other students, the twins, even before confronting the troll by way of unsafe broom usage. Point three see, and all that.
• He revealed his super-secret patronus that Dumbledore told him to keep secret, a super secret.
• He may have damaged His Father's Rock.
• He transfigured something that burns, specifically so that it would do so.
• He has committed himself to a course of action fundamentally at odds with participating in society in any reasonable fashion.

The transfiguration is probably the worst on the list, really. If Harry is lucid at the end of this chapter I expect there will be some throw away line, possibly post-timeskip, about Dumbledore taking measures to avoid Transfiguration Sickness from the gases escaping the troll's skull.

And, really, why did Dumbledore tell him to carry that damn rock? Did he know? Or has Dumbledore found it so useful to carry a large rock around that "get a big rock, keep it with you at all times" is in the top five things he'd tell his younger self if he ever got the chance? Seriously -- the fuck?

I wonder if this arc will be like the psychological sort of horror movie where there's lots of action in the first twenty minute and the rest of the movie is the people who aren't dead yet being mean to each other. I can see that kind of aftermath, here. It won't be pretty.

On the other hand, if the twins go sufficiently public about Harry's homid patronus then Lucius will find out about it anyway and there won't be any reason for Harry not to use it to communicate with Draco. At least, not until the restraining order shows up.

Seriously, having your stalker's glow-in-the-dark spirit animal bounce in through a wall at the most inopportune moments to remind you that they're still thinking about you and really just want to talk could lead a person to think maybe Azkaban isn't so bad an idea after all. Ugh.

Harry has shown again and again that he can't lose, and instead doubles-down. He did so with Hermione, and now Lucius has killed her. If people realise it's Lucius, all the better for him; nothing can be proved, but he shows himself to be extremely dangerous and willing to protect his family.

Without endorsing any part of this comment dealing with events which have yet to take place, I congratulate user 75th who receives many Bayes points for this:

http://lesswrong.com/lw/bfo/harry_potter_and_the_methods_of_rationality/6aih

Hermione is dead. Hermione Granger is doomed to die horribly. Hermione Granger will very soon die, and die horribly, dramatically, grotesquely, and utterly.

Fare thee well, Hermione Jean Granger. You escaped death once, at a cost of twice and a half your hero's capital. There is nothing remaining. There is no escape. You were saved once, by the will of your hero and the will of your enemy. You were offered a final escape, but like the heroine you are, you refused. Now only death awaits you. No savior hath the savior, least of all you. You will die horribly, and Harry Potter will watch, and Harry Potter will crack open and fall apart and explode, but even he in all his desperation and fury will not be able to save you. You are the cord binding Harry Potter to the Light, and you will be cut, and your blood, spilled by the hand of your enemy, will usher in Hell on Earth, rendered by the hand of your hero.

Goodbye, Hermione. May the peace and goodness you represent last not one second longer than you do.

When I first saw this comment, it was downvoted to... I forget, -6 or something. Going by the percentage score, at least 11 people downvoted it. From the replies, some people didn't like the tone of apparent certainty with which 75th spoke. Sounded uppity to them, I guess. It was at +3 before I linked to it on /r/HPMOR.

I wanted to say something at the time about that, and how penalizing people for sounding certain or uppity or above-the-status-you-assign-them can potentially lead you to ignore people who are actually competent, but at the time all I could say was "Why are people downvoting this? It's a testable prediction" whereupon it climbed up to above 0.

Everyone who downvoted 75th or agreed with the downvotes at the time, please take note. Speaking in a tone of what seems-to-you like inappropriate certainty does not always indicate that someone is arrogant. Sometimes they have seen something you have not.

There's some debate about whether the passage about Hermione's soulsplosion rules out becoming a Hogwarts-anchored ghost. I have offered a bet to chaosmosis (LW, Reddit) on Reddit on this topic - I am skeptical of any ghosts.

My friend and I were emailing about this update. I asked her for her opinion on it and whether or not she liked it. Here are her thoughts:

"Yeeah, I kind of don't. I posted this review on it yesterday (after quietly fuming for a bit):

If this had been Neville or someone, I'd be commending you on how you handled the emotion here, but as it is I was too annoyed and appalled that you were damseling and then fridging fricking Hermione while halfheartedly suggesting she put up an offscreen fight to be able to appreciate it.

I'm not easily annoyed with fridging, or character death in general. In fact, a lot of my favorite scenes in fiction involve my favorite characters dying, and I've always argued that a character of any gender dying as a vital part of the main character's arc is fine. But Hermione had a huge incomplete arc and you've just rendered the entirety of it pointless. This is Hermione, she wasn't as rational as Harry, she tried to be a hero but only made things worse, she was framed for murder and ended up in a huge debt to Harry, which she had plans to try to settle and potential for interesting emotional growth, except whoops, then she died, and nothing ever came of any of it. For shock value and unexpectedness purposes, I guess that's cool. But for storytelling purposes, it's breathtakingly unsatisfying, and the fact she was your primary female character by a mile and you just killed her off in an offscreen fight because a boy was too late to save her, her last words spent reassuring him it's not his fault, adds a bitter aftertaste of typical gendered tropes to the whole thing.

I'm hoping this isn't what it seems, one way or another, and Hermione gets to come back and do some of the stuff she should have gotten to do so that maybe at least some of the time you spent developing her wasn't just inane inconsequential filler. But if it is what it seems, I'm just emptily disappointed - too distracted sighing dejectedly at the fact I thought you were better than this to even care on an in-world level that she died.

A chapter like this shouldn't fall flat like that. Although my reasons for disliking it may be fairly meta and you could argue you're intentionally averting accepted standards of when characters cannot die, the ultimate result is just that I'm left unaffected by a chapter that should have been powerful and emotional. As an author you should care about that if nothing else.

Basically, remember when I was telling you that one of the few things that bugged me was how near the beginning Harry's interactions with Hermione where she was traditionally smart but he was rational seemed to be belittling her to glorify him? Well, the reason it didn't bug me that much was that Hermione was still interesting and seemingly getting real development and they story seemed to be giving her her own quest of self-improvement through which she could easily become his equal or better. Now she turns out to have existed purely to make Harry care about her and nothing she did mattered and she never got to be anything but Harry's less rational, less successful, less efficient, overemotional love interest foil. Argh. And we didn't even get to see her put up a proper fight! I wouldn't have minded nearly so much if, say, Harry had arrived to find Hermione had already killed or otherwise disabled the troll, with a victorious smile of contentment on her face, and died from her injuries as he watched while whispering "I did it, I'm a hero." But NOPE she put up some kind of fight and threw some explosive-looking spells but of course she was actually helpless and couldn't possibly have defeated the troll on her own so her survival completely and utterly depended on Harry making his way there in time which he didn't, oh no, look at his sadfeels while all she cares about is telling him it's not his fault instead of being livid that she didn't achieve fucking anything in her life because Harry constantly overshadowed her and now she's dying before she could figure out how to fix it.

All that made me too angry to give a damn about the plot or emotion or anything, which is a shame because otherwise I'd probably have enjoyed this update."

High-confidence prediction: Chapters 88-89 are Snape's doing.

I'm tentative to make predictions here since, reading through comments, I consider you folks more grounded in rationality, logical thinking and also fictional predictions than me. But I wanted to share a thought and get feedback, so here goes.

My interpretation of the big magical release goes like this: Hermione's brain, experiences, knowledge, magical ability, etc., are programmed via the genetic magic marker to upload into... something. The Atlantean Neural Database, or something like that. We've got reason to believe that magic was artificially created and the genetic marker programmed into people, so that they are capable of interfacing with reality on a far more interesting level than most people. We've also got plenty of evidence to suggest that the brain is, if not fully understood by magical knowledge, more than capable of being interacted with. We have Legilimency and Obliviations capable of accessing memory, thoughts, knowledge, and intentions; the author is capable of working with things WE don't know about because wizarding knowledge is stated to have been lost, so we also have some unknown-unknowns working against us. So the odds of neural magic having existed in a more advanced form (peaking in Atlantis) seems pretty decent to me.

If I imagine myself as a group of wizards (or an ultra clever protoMerlin), capable of interacting with time and brains, and I'm still interested in doing research and data gathering, then it seems like being able to collect ALL neural data on ALL wizards would be a big boon in doing research. So the magic marker, given a certain degree of trauma, could trigger the release of information back to the source of magic. Dumbledore's certainty that Hermione is dead (despite certainty in other comments that HP should still be capable of preserving her brain) tells me that he knows, based on that big blast of magical resonance stuff, her death is now as official as it gets. He's also very confident that life goes on after death; if you're capable of uploading every part of your brain that makes you YOU into a big database, there's no reason for him to be wrong, in this sense.

And from a narrative perspective, the fact that Harry immediately jumps to conclusions about Atlantis and searching outside of time to bring her back--no to protect everybody else from death, as was his original statement, but to specifically fetch the string of information that represents Hermione and restore it to existence--suggests they're related.

Maybe I'm late to the party on this idea though. Odds of somebody else thinking of it before, especially if I'm the one thinking about it, seem pretty good.

I predict that Harry will save many or all people who ever died from oblivion with magic that reaches backward through time to capture the mind of each person at the point of their death.

I further predict that this magic will create the mechanism of magic, possibly incidentally, and be responsible for the sort of Atlantis that magical Britons believe in.

I speculate that magic and ghosts are unintended byproducts of Harry's Afterlife Immortality Project.

Harry is an anti-death hero. Whatever villains he may encounter, his enemy is death and his heroic victory will be over his true enemy.

The afterlife figures centrally in the original work in ways that are incompatible with the author's worldview. In this way, the author incorporates important elements of the original work without betraying his convictions.

I made this prediction last April, and wish there had already been an admonishment to share predictions like the one involving 75th, yesterday.

Prediction for Chapter 90: Time Pressure, Part 3:

"Wait a moment," you say. "Time Pressure, Part 3? Harry already lost his race against the clock. Why would Chap. 90 be called 'Time Pressures'?"

Because Harry's race against the clock to save Hermione's life has only just begun, and he has slightly less than six hours left. Eliezer mentioned that one of his most significant purposes of Chap. 86 was to update characters' states of knowledge before the next arc. If you recall, in that chapter, Harry learned the word "horcrux." And in Chap. 87, Harry learned of the philosopher's stone.

So what will Harry do? Get the shell removed from his time turner, or obtain a time turner from someone else. Learn about the Horcrux ritual as quickly as possible, travel back in time, get Hermione to create a horcrux, and erase her memory of doing so thus that her death plays out just as before. Then start working on the stone to restore Hermione to life. (He could also take the "bone of the father, flesh of the servant, blood of the enemy" route, but positively identifying Hermione's enemy could be difficult. Lucius Malfoy and Company, who were tricked into antagonizing Hermione, might not count for purposes of the ritual.)

The hard part, of course, will be getting Hermione to kill, but Harry can probably find someone in a hospital who has only days to live and convince Hermione that creating a horcrux is a net ethical positive.

Without Hermione's death, murder would have been a line Harry was unwilling to cross. I think that whoever is behind this plot really wants Harry to cross the Moral Event Horizon and/or create the stone (the second possibility is less likely though, since Hermione was already working on the stone, but that fact could have been unknown to the plotter).

Edit: As of Chapter 101, this prediction has probably been proven wrong, unless Harry's memory of executing this plan has been erased (not completely impossible; there's a moment when he becomes momentarily disoriented.) But I think this would make a totally awesome piece of recursive fanfiction. After HPMoR is finished, I might write this.

I predict that it will be revealed that Quirrell or a closely related entity has been abusing Harry on and off throughout his life, to try and make him into a Dark Lord.

He can go to Harry's house like the time he played Father Christmas.

Obliviated memories leave residue, which is how in Chapter 88 the twins remembered that they could find people, in the castle, but couldn't remember how.

In the first chapter, Harry noticed that he believed in magic.

some part of Harry was utterly convinced that magic was real

In chapter 16, Harry is almost reminded of something when he looks at Quirell, but can't remember what. And when Quirrell is first introduced, Harry ominously recognizes him

"Professor?" Harry said, once they were in the courtyard. He had meant to ask what was going on, but oddly found himself asking an entirely different question instead. "Who was that pale man, by the corner? The man with the twitching eye?"

"Hm?" said Professor McGonagall, sounding a bit surprised; perhaps she hadn't expected that question either. "That was Professor Quirinus Quirrell. He'll be teaching Defence Against the Dark Arts this year at Hogwarts."

"I had the strangest feeling that I knew him..." Harry rubbed his forehead. "And that I shouldn't ought to shake his hand." Like meeting someone who had been a friend, once, before something went drastically wrong... that wasn't really it at all, but Harry couldn't find words.

In the sixth chapter, McGonagall points out that Harry can act like an abused child.

sometimes, you say or do something that seems very much like... someone who spent his first eleven years locked in a cellar.

Quirrell uses Obliviation and memory charms and as Mr. Cloak-and-Hat, he manipulated Blaise. And he uses Obliviation and memory charms more subtly, to change someone's mood and personality over time, as shown when he brute-force-save-scumed his way to making Hermione suspicious of Draco.

Quirrell expected Harry to become a Dark Lord when he spoke with him after the first class and was surprised that Harry aspired to science.

Quirrell expects the worst out of people, and so he expected that an abused Harry would be destined to darkness.

Edit: I just realized that Harry was probably abused almost every night (or day) for some significant period. There was a time turner involved, and that's why his sleep cycle is off.

Legs eaten off at the thighs! For some reason this stuff reminds me of the fight scene from the fifth Twilight movie. Here's a great video review describing that scene, it really brought a smile to my face.

I haven't visited these threads for nearly a year; please forgive me if someone else has shared a similar prediction in the meantime.

I predict that Quirrell's goal is to start a war between magical people and non-magical people.

The student armies have been taught combat skills, organization, and discipline but they have not been indoctrinated. The text does not show that the student armies have been guided toward one faction or another within Magical Britain. Quite the opposite, they have been taught to work together across the 'house' lines that may have divided them in the past.

It would be counter-productive to prepare tools that could be as easily used by your enemies as yourself. So we may reason that all members of the student armies are already on the side Quirrell wants them on. One thing all members of the student armies have in common is that they are members of Magical Britain.

I have found nothing to suggest international tensions, so a war against another magical nation would be out of place in the text, as I understand it.

On the other hand, Quirrell had a downright emotional reaction when Harry declared his aspiration to be a scientist in chapter 20. After the end, when we read through the story from the beginning, we will see that as the point where the villain's motivations are revealed: Quirrell wants to save the world from scientists and their careless exploration of powers they cannot contain.

Quirrell has been pushing Harry down a path of isolation. He created situations that built up Harry's distrust of authority. He cut Harry off from his friends. I believe he means for Harry to trigger the Great Muggle War by doing something grand and ill-advised that makes sense in the desperate state Quirrell intends to put him in.

My prediction of Quirrell's overall goal does not depend on my prediction of his intentions regarding Harry, and I am less certain of those. I feel there are pieces I am missing there.

Two interesting observations: The most recent utterances of the words "temporal pressure" (similar to the titles of these last two chapters) was in chapter 86 when discussing the Halls of Prophecy:

""The Hall of Prophecy," Minerva whispered. She'd read about that place, said to be a great room of shelves filled with glowing orbs, one after another appearing over the years. Merlin himself had wrought it, it was said; the greatest wizard's final slap to the face of Fate. Not all prophecies conduced to the good; and Merlin had wished for at least those spoken of in prophecy, to know what had been spoken of them. That was the respect Merlin had given to their free will, that Destiny might not control them from the outside, unwitting. Those mentioned within a prophecy would have an glowing orb float to their hand, and then hear the prophet's true voice speaking. Others who tried to touch an orb, it was said, would be driven mad - or possibly just have their heads explode, the legends were unclear on this point. Whatever Merlin's original intention, the Unspeakables hadn't let anyone enter in centuries, so far as she'd heard. Works of the Ancient Wizards had stated that later Unspeakables had discovered that tipping off the subjects of prophecies could interfere with seers releasing whatever temporal pressures they released; and so the heirs of Merlin had sealed his Hall. It did occur to Minerva to wonder (now that she'd spent a few months around Mr. Potter) how anyone could possibly know that; but she also knew better than to ask Albus, in case Albus tried to tell her. Minerva firmly believed that you only ought to worry about Time if you were a clock."

Next, near the end of chapter 89, Harry "turns away from Dumbledore" twice, almost as if there's a kink in time after explicitly mentioning "pressure":

Harry opened his mouth to scream out all his fury, and then closed it again. There wasn't any point in screaming, it wouldn't accomplish anything. The unbearable pressure rising inside him couldn't be let out that way.

'Harry turned away from Dumbledore and looked down at where the remains of Hermione Granger were lying in a pool of blood ... another part of him already knew that this event was real, part of the same flawed world that included Azkaban and the Wizengamot chamber and

No

With a fracturing feeling, as though time was still torn to pieces around him, Harry turned away from Dumbledore and looked down at the remains of Hermione Granger lying in a pool of blood with two tourniquets tied around her thigh-stumps, and decided

No.

I do not accept this."

Hypothesis: Something very strange just happened to Time around Harry, possibly involving a time turner, and things are definitely not as they seem.

It's almost as if someone is trying to manipulate Harry's reaction to these events, like when H&C tricks Hermione repeatedly. Fred and George are unconscious at this point, too. It goes without saying that Harry is probably an unreliable narrator.

And thus, Hermione Jean Granger was permenantly sacrificed in a ritual which manifested Harry Potter.

I think I've identified three techniques Eliezer uses to create associations in the readers' minds and promote ideas to their attention.

There's repetition. If you're sensitive to repetition then the repetition will drive you mad. Five false prophets, many uses of Grindelwald's name, and about a zillion instances of the phrase 'the old wizard'. Dumbledore is old, old, old.

There's placing two related ideas side by side. Like Harry wondering how magic could possibly work, then segueing into an 'analogy' to artificial intelligence. (Repeatedly, so it's a twofer.) Or the description of phoenix travel appearing in the same chapter as Harry confronting Dumbledore over Narcissa's death.

And there's the throwaway gag that contains the literal truth. "It's not like I'm an imperfect copy of someone else." "Let me know after it turns out that it was Professor Quirrell who did it."

And, perhaps, "And if you coincidentally crack the secret of immortality along the way, we'll just call it a bonus."

After Chapter 87, I thought it likely that Hermione's primary contribution to the story would be to rediscover the Philosopher's Stone through the application of the scientific method, solving humanity's biggest problem with the method humans actually use to solve their big problems. It's a natural fit for her talents, it teaches the lesson that saving the world with science is no less heroic than wandplay and derring-do, and it's a goal she could pursue if her magic deserted her, as it may have just done.

The problem was, Hermoine had a heroic task, but not a heroic motive. And of course she has bigger problems now. They're problems for the story as well. Judging by the number of words he's spent on the subject, it looks like one of Eliezer's goals for HPMoR is to teach us his ideas of what it means to be a hero. Hermione's premature death spoils the lesson. The story's told us that she's a hero, but she never finished becoming one. She never found something to protect.

So. I'm confident that she'll return, and that death will be her Azkaban, the injustice that calls her to action. I rather think her heroism will take the form of research into a source of immortality. This will require Harry's means of restoring her to life to be insufficiently general to help the rest of humanity, but I have no idea what Harry's going to do so I think I'll end my speculations here. Am I on the right track?

I'm sad now.

Those of you who didn't read canon before reading this, there's a corresponding incident in the first book which I think would add to your understanding of this incident. Quirrell sneaks a troll into the school, but Harry, Ron, and Hermione are improbably able to defeat it using the first thing the Weasleys try here (smacking it with its own club). The difficulty level of that encounter was clearly calibrated to the characters' strengths in a way common in heroic stories and I think Eliezer was deliberately subverting that expectation. (He's made this point in the sequences on a few occasions - something about how it's allowed for Nature to just throw problems at humanity that are too hard for it - although I can't find a quote at the moment.) I particularly appreciated how Harry only used tools that he had deliberately prepared in advance, sometimes way in advance, e.g. the healer's kit.

I also wonder where Fawkes was while this was happening. You'd think he would've found his way to either Harry or Hermione. 

I have a mild complaint about all these cameos. Some of the names of the people who end up getting cameos don't fit in the Harry Potter universe to my ear and they stick out really noticeably. One of the first things I'd do if I were hypothetically rewriting HPMoR for publication is to come up with a consistent and meaningful naming scheme.

Hermione's cheeks were going even redder. "You're really evil, did anyone ever tell you that?"

"Miss Granger," Professor Quirrell said gravely, "it can be dangerous to give people compliments like that when they have not been truly earned. The recipient might feel bashful and undeserving and want to do something worthy of your praise.

High-entropy, low-confidence theory I'm going to throw out there: Trelawney's prophecy refers to Death with a capital D, not to Harry. Someone (like a time-traveling Harry) summoned Death around the time Trelawney spoke.

I'm actually very very bothered by "0.3% of the speed of light". This is 900,000 meters/second. A passenger airplane flies at slower than 300 meters/second. Harry is flying 3000 times faster than an airplane?

Let's say a broom accelerates a thousand times faster than a car. A car can go to 60 mph in 7-8 seconds. Let's say 5 seconds. That's an acceleration of about 5 meters/second squared. Let's say Harry accelerates 5000 meters/second squared (an impossibly large acceleration). It would take him 3 minutes to get to that speed. All the while experiencing 500 G force, that is 500 times the force of gravity. The record G force survived by a human is 46.2.

Seriously. This is 9000 football fields in ONE SECOND. He can't possibly be making those turns and bumping the Weasleys like a bludger. He'd be killing them all (in a fraction of a second). Throw in some more zeroes please! 50 meters/second (about 100 mph) is the limit of what I find believable.

I will throw in several predictions. I myself am not completely confident of some of those.

1. Time-turners, prophecies and similar devices, which predict that something will happen, work by exerting some mind control upon people in the form of unexplicable urges, such as the urge to take the left turn this one time. I'm not sure how far can they go in order to fulfill themselves.

2. The events in the magical world are not just dictated by the already-discovered laws of physics, but also by the laws of fairy tales. Dumbledore is pretty damn rational, at many points more rational than Harry (he might even be more rational overall). His reasons for having an evil Potions master aren't simply because this happens in fairy tales. The Universe liked it more if that was the case, so he was probably represented with an evil person who is highly suitable for the Potions position, or something like that. Dumbledore is most probably aware of this law. After Harry case the true Patronus and Quirrell asked him where he'd hide something, Harry gives 5 places: volcano, inside earth, deep in the ocean, somewhere in the air, and in space. Fire, Earth, Water, Air, space-thingy. He can't have said that by coincidence, and this is evidence of that law existing. Quirrell's reaction indicates he's aware of the law.

3. Part of Voldemort is in Harry. The Sorting Hat either lied, or more likely, Voldemort isn't in his scar - Harry asked about his scar (I realized that much before it was reminded in chapter 90 or 91 and therefore have read a lot of HPMOR with that in mind), but it may still be inside Harry, just not in the scar. Evidence: his unusual 26-hour sleep cycle was probably inherited; he is exceptionally intelligent, and just 11, while his parents aren't particularly intelligent (intelligence is usually mostly inherited genetically); he is better with a broomstick than children who have used broomsticks before going to Hogwarts; his dark side seeks destruction (Voldemort appears to seek destruction too), and is very cold (from his flashback, Voldemort's voice is really quite cold). This probably happened by accident, rather than as a plot - it may be explained with the law from 2. - Voldemort tried to kill Harry, the universe interfered in the simplest possible way, although I'm surprised as to why did the universe let Voltemort find Harry in the first place then.

4. Quirrell is not Voldemort. I'm still very perplexed by Quirrell, but it would make an awful, predictable plot to have him be Voldemort. He does appear to be a Dark wizard, the Monroe story seems implausible (he doesn't believe in others' love, why would he be a hero? Unless he did that for himself). He probably has a lot to do with Voldemort, but they were neither friends nor enemies. I don't know about the sense of doom, but it probably is connected with what happened when Harry's parents died. It appears that Quirrell doesn't know about it, either - therefore it is probably because he could not see an explanation, because the explanation involves love, and isn't obvious.

5. Voldemort is the one who will (at least try to) TEAR APART THE VERY STARS FROM HEAVEN. He seems to be all about destruction, though I'm not sure why, and I'm not sure why does he not take the shortcuts Harry had in mind, and this is the weak part of this prediction. Perhaps it is the universe's will that people must die for a good reason, rather than having the world's strongest wizards destroyed by a handful of highly toxic molecules each.

6. Magic is like that because it is made by humans. This is probably obvious - magic came to exist by humans, this is why a lot of it only make sense in terms of human intuitions, and not so much sense in terms of laws of physics. I'm still very puzzled by the fact that it appears to violate the laws of physics. It also sounded like magic might be a superintelligent AI, but I forgot my arguments for that.

I also wonder, what would happen if you use a time-turner to do the impossible, for example talk to your older copy, so when you see the newer copy, don't time-turn. Would it turn out that someone strongly felt like approaching you while Polyjuiced as you? Is it that nobody would ever think of that in the wizarding world? I'm sure there's a lot more going on with time-turners.

HPMOR prediction of low confidence: The Weasleys' use of the deligitor prodi spell gives Harry a good way to access high-level magical artifacts. If the Hat shouts 'Gryffindor!' to the Weasleys, might it not shout 'Ravenclaw' to Harry? There are no magical items from canon other than maybe the stone that I would expect Harry to want more than the Diadem. And surely Harry has the proper motive to use the Hat, regardless of whether it would require a Ravenclaw or a Gryffindor motive to get the diadem.

Quirrell can feel Harry's emotions. This can partially explain at least some of the cases when he unexpectedly realized what Harry was thinking (for instance, this probably gave him some information during their conversation about Parseltongue). It might be worthwhile to find all cases when they talked and Harry attempted to hide his emotions.

In the intervening hours did Hermione have any interesting thoughts about the Philosopher's Stone? Will Harry shortly?

"Time Pressure" is a pun! Somewhere previously, prophecies were described as being caused by a sort of pressure built up on time, and TP2 ends in a prophecy.

It appears Quirrell now believes Harry has used the killing curse. Applying Story Logic, this misjudgement of Harry will lead to Terrible Bad Consequences for Quirrell.

Some ramblings before ch90: Quirrell will not learn the truth of how Harry killed the troll, since Dumbledore will memory charm the Weasely brothers (they saw Harry's patronus) and thus discover that their minds have been tampered with (by Quirrell). Suspecting Quirrell, Dumbledore will also erase the Weasely brothers' memories of how Harry actually killed the troll. Quirrell will not actually see the dead troll. He will not be told how it died.

If Dumbledore does not find memories of the maraurder's map in the Weasely brothers' minds, he may well make the Quirrell=mort connection immediately: Dumbledore used the map to unsuccessfully locate Tom Riddle, and only a professor could have tampered with the minds of students who have been in Hogwarts this whole time.

From Chapter 6:

Harry was examining the wizarding equivalent of a first-aid kit, the Emergency Healing Pack Plus. There were two self-tightening tourniquets. A Stabilisation Potion, which would slow blood loss and prevent shock. A syringe of what looked like liquid fire, which was supposed to drastically slow circulation in a treated area while maintaining oxygenation of the blood for up to three minutes, if you needed to prevent a poison from spreading through the body. White cloth that could be wrapped over a part of the body to temporarily numb pain. Plus any number of other items that Harry totally failed to comprehend, like the "Dementor Exposure Treatment", which looked and smelled like ordinary chocolate. Or the "Bafflesnaffle Counter", which looked like a small quivering egg and carried a placard showing how to jam it up someone's nostril.

From Chapter 89:

"Fuego!" / "Incendio!" Harry heard, but he wasn't looking, he was reaching for the syringe of glowing orange liquid that was the oxygenating potion, pushing it into Hermione's neck at what Harry hoped was the carotid artery, to keep her brain alive even if her lungs or heart stopped, so long as her brain stayed intact everything else could be fixed, it had to be possible for magic to fix it, it had to be possible for magic to fix it, it had to be possible for magic to fix it, and Harry pushed the plunger of the syringe all the way down, creating a faint glow beneath the pale skin of her neck. Harry then pushed down on her chest, where her heart should be, hard compressions that he hoped was moving the oxygenated blood around to where it could reach her brain, even if her heart might have stopped beating, he hadn't actually thought to check her pulse.

The oxygenation potion also slows circulation. Did Harry accidentally kill Hermione? Would the potion have unintentionally prevented blood flow to her brain by retarding flow in her carotid artery, while unhelpfully oxygenating her neck? It makes sense that a potion designed to prevent the spread of poison would prevent movement of the blood. It's also stated that it works on "a treated area." If it's primarily meant to slow the spread of poisons from bites, the spell's "treated area" might be defined as the volume of flesh a certain distance away from the injection site.

Also, giving CPR to someone when their heart is still beating is definitely not good for them.

What with the timey-wimey shenanigans in the writing and her brain not having spent too much time "dead" yet, I'm suspecting Hermione will yet live.

What with the show and Dumbledore's diagnosis, I'm suspecting Magic will continue to think her dead and thus her career as a witch being over (pending Harry hacking the Source of Magic).

Plus repercussions of the "Do not mess with time" kind.

Bearing in mind that Eliezer consistently foreshadows important events, let's brainstorm what Harry might do to end the world.

First, ritual magic and Dark rituals have played a prominent role in the story. Dark rituals have been mentioned over and over, and it's been emphasized that they are dangerous and powerful.

A magic ritual, much like a magic potion, seems to achieve much more than a spell. In my opinion this is probably because of the same conservation law by which potionmaking uses a small amount of magic to unlock the power already in some sense inherent in the potion's ingredients. (Example: Lily Potter sacrifices her life and successfully provides Harry with lifelong magical protection, while not even Dumbledore is capable of casting such a spell even with the Elder Wand.)

In fact, I conjecture that Eliezer brought potions into the story the way he did as a way of making us aware of this magical conservation law. A potion, to my mind, is merely a certain class of magic ritual which produces a magically potent substance. I may be wrong, since we don't know that potionmaking obeys the same ceremonial formula as a ritual.

Here's Quirrell's description:

An ordinary Charm, Mr. Potter, can be cast merely by speaking certain words, making precise motions of the wand, expending some of your own strength. Even powerful spells may be invoked in this way, if the magic is efficient as well as efficacious. But with the greatest of magics, speech alone does not suffice to give them structure. You must perform specific actions, make significant choices. Nor is the temporary expenditure of your own strength sufficient to set them in motion; a ritual requires permanent sacrifice. The power of such a greater spell, compared to ordinary Charms, can be like day compared to night. But many rituals - indeed, most - happen to demand at least one sacrifice which might inspire squeamishness. And so the entire field of ritual magic, containing all the furthest and most interesting reaches of wizardry, is widely regarded as Dark.

So, I think Harry will either discover or, equally likely, invent a magic ritual which sacrifices something really ... squeamishness-inducing ... in exchange for root access to the Atlantean mainframe, or whatever.

Some of the comments on what Harry should do reminded me of something that has yet to, as far as I know, appear in HPMoR: The Room of Requirement (aka "the god room"). In canon, Dumbledore (apparently) didn't even know about it; it was Dobby who revealed it to Harry, and hence the DA; I don't remember there being an explanation for how Draco found it (maybe Dobby knew about it before Order of the Phoenix, and Draco ordered him to tell him about it?). It also had some poorly defined, but clearly restrictive rules, which Neville eventually mastered over the course of Deathly Hallows (if not off screen in the previous books): it can't provide food, it didn't show Harry what Draco was up to based on the way Harry was requesting, there was something about what conditions prevented people from entering that I don't remember in detail, etc. It clearly wasn't much use at conjuring up god-mode equipment for use outside of the room, since Neville didn't use it as an armory for the final battle.

I don't remember this being mentioned among the "not appearing in this fic" elements of canon, though it does strike me as ridiculously overpowered in this Harry's hands. However, canon Riddle used it to hide Ravenclaw's diatem, which suggests that canonmort knew enough about the room that rationalmort would almost definitely have found it and abused it for all it's worth if it exists in HPMoR. (It seems to have a decent supply of books, at least, though I have to doubt it could generate information that wasn't put into it beforehand.)

Thinking about the RoR also reminded me of that two-way vanishing cabinet connecting Hogwarts to Borgan and Berk's, which I'm rather doubtful JKR thought much about before Order of the Phoenix, since at some point since it's creation, enough people will have had to have been put through it to make the connection and exploit the blatant hole in Hogwarts security.

Most of the plans to use time turning to fix this are massively overly complicated, by the way. Best bet is to swap the oxygenating potion for something which will make her death less permanent.

Which Harry can find or have made in < 6 hours.

Options: 1: Elixir of life. The stone is at hand, Snape is at hand. It is possible that shout is what taking it looks like. 2: Undeath. The potter verse does have vampires, and they are integrated in magical society at least to the extent that seeing one in a bad neighborhood is not grounds for an auror raid. Werewolf infection might also do it. 3: Draught of living death?

... On a side note.

Hermione Granger, of House Potter, at great cost to House Potter, was just killed on Potter's watch.

What will it take to give Harry a breakdown, to have him say, or think, "this is too much"?

At the start of this story he's human, vulnerable to stress; merely facing up to Minerva McGonagall is enough to make him have to excuse himself and go retch. When I consider everything that's happened to that boy since then, it's a wonder he's not in need of therapy. But now his strength and sanity seem inhumanly unerodable; even Hermione's death immediately leads to an "unyielding resolution" that he's going to get her back.

Hmm. It seems highly likely that the troll was timeturned back six hours itself in order to prevent people using time turning against it - given the amount of prep work that went into this (sabotaging Hermoine's kit, lifting the map, making her miss that meal. sun proofing it...) it would be a major oversight to not do that. Of course, that limits the suspect pool to people who know about time turning. From our perspective, all relevant suspects do, but in universe, this probably does rule out people. For example, if means Lucius may in fact know that it was not one of his minions getting overly ambitious.