Here is my best attempt at a delaying tactic, after sleeping on it. Please tear apart/suggest better ways in which LV might tear apart, to replace the poor placeholder responses he has here.

--

"Agree that I musst die, if it ssavess world. But thiss iss not besst way to kill me. Ssee how you can benefit more, given your goalss."

"Explain."

"Believe power you know not doess refer to power to desstroy life-eaterss. Life-eaterss will find you eventually, teacher. Know you. Will hunt you down, ssomeday. Eat all of you, all of world and magic, in the end."

"Sso you will give that magic to me, now."

"You can never reach needed sstate of mind - incompatible with deadly indifference. Sschoolmasster could never casst - incompatible with acceptance of death. Majority cannot casst, and in the tessting, sstandard defence againsst life-eaterss iss ssacrificed. Will weaken your alliess greatly, should I randomly try to teach."

"What do you proposse, then?"

"Take me to life-eater prisson. Allow me to pour out my life and magic there, eradicate them wholly. How I wisshed to do sso, during the resscue! You called me back, then."

"..."

"Many advantagess to you in thiss. Can decimate your final enemy, wipe out their greatesst colony, certainly buy you yearss. Removess them before Wizengamot'ss death throess can releasse them againsst you. Freess your remaining alliess, ass thosse here failed to do. And I am utterly desstroyed - can leave no ghosst behind me. Nothing to fuel ssecret devices of Sschoolmasster's. Presumably, reduced rissk that your great creation will recognisse my spirit - for I doubt you have tessted that."

"You will not desstroy all of them, and sso I will have to find another ssolution anyway."

"Ssolution iss girl-child. Sshe iss closse to learning sspell, and now immortal. My death could drive her to hunt life-eaterss forever; thiss iss not beyond your sskillss at manipulation. You know sshe wantss to be a hero."

(EDIT: I thought about this some more, produced a better solution, submitted it as a review, and also posted it here)

1. Voldemort knows that Harry possesses an altered version of the Patronus spell, and something else that affects dementors, but not the spell's nature. Harry can buy time by offering to explain how these work, by doing so, and negotiating for more names. Harry can truthfully say that learning certain things about the Patronus and about Dementors will have side-effects that Voldemort may not want, and that this means he needs to think about what to say. Voldemort will surely exert time pressure, but can only speed this up by so much if he wants to fulfill his goal of gaining all of Harry's secret powers. He can also try to convince Voldemort to let him cast his modified patronus; this is very unlikely to work, but should be done anyways because seeming to not try any tricks would itself be suspicious.

2. A winning strategy should simultaneously disable all of the death eaters present and Voldemort himself. Voldemort will be disabled if their magics touch, especially if that touch can be sustained.

3. The main weapon at Harry's disposal is partial transfiguration. I spoke first of buying time, because we also know that transfiguration takes time, although we don't know all the details of how the time requirement is determined or where in the process there is first external evidence of a transfiguration in progress. Harry has already practiced transfiguring thin cross-sections through things, and used this power in anger twice (in Azkaban and against the troll), so he should know what he can do there, how long it will take, and when it will become visible.

4. Harry can only transfigure something that touches his wand. So he transfigures a narrow segment starting at his wand, passing through himself into the ground, and proceeding from there.

5. Since one turn of Harry's time turner remains, if a plan ends with Harry recovering his items, then there may be an extra invisibility-cloaked, fully equipped copy of him nearby. While there is a charm that Voldemort could have cast which would detect if that were so, we don't actually see him cast it. However, the resonance effect would reveal his presence; so instead, if Harry manages to time turn and escape, he should immediately contact and lend his cloak to Mad-Eye Moody.

6. If Harry can get a partial transfiguration off, there are a ton of possibilities. Harry has recently learned how, in a complex transfiguration, to control the order in which parts appear. So these options are not mutually exclusive; he can perform several or all of them at once.

   • There is a time turner nearby, in a pile of objects on the floor which no one is paying much attention to. He can modify the floor under it, flipping it over.
   • There are objects transfigured by Voldemort nearby (false teeth), in the same pile; if Harry's transfiguration touches one of them, it could cause resonance. Many of the other objects in that pile will also be enchanted by Voldemort's magic; transfiguring the entire surface underneath the heap would strengthen the effect. (This is important because Harry's transfiguration can't reach Voldemort himself, since Voldemort isn't touching the ground).
   • There is a Hermione horcrux nearby, which activates by touch. What "touch" means in the context of partially-transfigured cross sections has not been nailed down, but if that does count, then Harry can cause the hermione horcrux to simultaneously touch all of the death eaters. Furthermore, he can cause it to not simultaneously touch himself, by transfiguring a bit of floor into a delay switch, and lifting up his foot after the transfiguration is complete.
   • There are weapons Harry can make with low volume and low mass. If the configuration is not too complex for the time available, he could try transfiguring a cross-section that passes through the brains of each of the death eaters.
   • Hermione is nearby, asleep. She will wake up if a little bit of her skin turns into acid.

Ideally, he would do all of these things as part of the same transfiguration; but that might be too much.

I wrote a version of this up at reddit too, but it seems to me trying to hack the laws of physics is wasted effort when we know very little about how magic works in concrete terms. We don't know what Harry can really do, how fast he can do it, or whether Voldemort would notice.

What we do know are: * how Harry thinks * how Eliezer thinks * what Voldemort wants

So we should be looking at things Harry could say that would advance his goal of surviving rather than trying to come up with a combination of spells, with the understanding that winning ideas are probably going to cluster around narrative interventions that EY thinks are interesting or important. A few that spring to mind:

Memetic hazard: are there things Harry could say or bring to Voledmort's attention that would pose an existential risk to him if he harms Harry

Let the AI out of the box: is there something Harry can offer Voldemort such that Voldemort goes against his stated agenda

Precommitment / timeless decision theory: are there ways Harry can manipulate the unbreakable vow to force certain conditions in the future

Learning to lose: what if Harry surrenders and agrees to join Voldemort, with a commitment Voldemort finds convincing

Unintended consequences: Harry makes a convincing case that there is no way to outthink an inevitability other than to fulfill it in terms that are advantageous to you.

I really think didactic lessons about rationality are going to be better, and more appealing to EY's sensibilities, than trying to fanwank some way to use magic to kill 38 people in a single play. We just don't have the rulebook for that.

Here is my tentative submission to FF.net. Please comment.

I decline to help Harry out of the box.

Harry no longer has Harry-values; he has unbreakable-vow-values. He is smart, and he will do whatever he can to "not destroy the world." In the process maximizing the probability of "not destroying the world," he will likely destroy the world.

If you would allow me, I would like to appeal to Voldemort's rationality and cast Avada Kedavra on Harry before he says or does anything.

I do not think I will be able to stop other people from getting Harry out of the box. I expected people to believe me when I tried to explain why we should not let Harry out of the box. They did not. It was frustrating. You have taught me a valuable lesson about what it is like to be an FAI researcher. Thank you.

EDIT: I have posted it.

I posted a longer form of this as a review / solution. Here's a condensed version:

Partial Transfiguration works through a deep understanding of physics. It allows Harry to to create any physically valid state of the universe, as long as he can hold it in his mind.

What this means is that you don't need to Transfigure a gun in order to fire a bullet. You can just Transfigure a bullet in the state of having been fired.

This is what the ability to Transfigure any physically valid configuration really means. You don't need to make a bulky laser weapon. Just make a laser pulse: an arbitrary amount of high-energy photons, aimed in the right direction. Instead of a shaped explosive charge, make a shaped explosion. Instead of antimatter, make gamma rays. Instead of a black hole, dangerous to everybody near it, make a bunch of gravitons and aim them at your enemy.

So given all that, how should Harry kill his enemies?

Lasers are messy weapons. Even black robes are reflective in some wavelengths. Use too much energy and you'll get a fireball back in your face. Release the energy too quickly and it will create an explosion instead of steadily boiling away your target.

Kinetic energy is safer. Transfigure a set of diamond missiles-in-flight, one aimed at each Death Eaters and one also for Voldemort, who is conveniently floating behind them. Giving them a speed of, oh, 0.005c should do nicely. They should be as large as possible - in order to leave large holes - but, since the difficulty and length of Transfiguration scales with the size of the target form, they will be flat and thin: head-sized and a millimeter thick, lying on the ground in front of Harry until the moment when, Transfiguration completed, they instantaneously acquire the forward velocity (and some angular momentum) that will have them impacting the Death Eaters' masks a few microseconds later. The slight layer of air turned into plasma carried in front of them will serve as a nice bonus.

Transfiguring the ground in front of Harry, if possible, is the best solution. Lacking that, pieces of Harry's legs will serve. Since Transfiguration can change the size and mass of the subject, the resulting wounds need not be deep.

If Transfiguration scales with the diameter of the target form, rather than its volume, we will reluctantly use much smaller bullets. A thousand diamond squares, one centimeter across and a millimeter thick, will form a sheet 31 centimeters on a side: much smaller than a car battery. An average of 26 .40 caliber bullets per head should be sufficient to the task.

Harry hisses "You have missinterpreted prophecy, to your great peril, becausse of power I have, but you know not. Yess, you are sstudying sscience, but, honesstly, you are yearss behind me. It may be that thiss power you know not iss ssomething I have at thiss sspecific time, that you will not know for too many yearss hence.

Before I explain, remember my Vow, and know my honesst intention not to desstroy the world, Vow or no. Now, do you know why I would tear apart the very sstarss? Do you know how? Not to desstroy the world, but to ssave it from whatever threatss require more energy to extinguissh than exisstss in thiss entire ssolar ssystem. There are more thingss in heaven and earth, Dark Lord, than are dreamt of in your philossophy.

I would usse sstar lifting to do it ssafely. In a way, I really would end the world to ssave it, ssince once humanss are out of the cradle, sspread through... er, let uss ssay 'heaven' in Parsseltongue, to mean well beyond thiss planet, why not add the masss of the Earth itsself to the sstuff of the sstarss, to yield that much more energy? And sso, if you avert thiss prophecy, there iss sseriouss rissk you doom yoursself! Are you willing to take that chance?

And why were you the one to hear thiss prophecy, Dark Lord? Why are you the one to causse it or avert it? What iss your abssolute advantage? Not in killing. Killing is eassy. Thiss iss your blind sspot cossting you much more in expected value than lasst time if you do not lissten.

You are the one becausse you have come clossesst by far, ass far ass I know, to true immortality, though thiss project iss not yet complete, elsse prophecy would not concern you to degree it obvioussly doess. Usseful sstar lifting will take time; much more than ussual lifesspan.

Ssupposse you heard thiss prophecy becausse you are to sshare thiss advantage with me, and together we will tear apart the very sstarss in 'heaven' to prevent ssomething actually bad! Ssomething we both may know nothing of yet, though I already have guesssess; and you know thiss project iss likely to go fasster with me than without me. Your lack of complete immortality meanss time may not be on your sside.

All I have ssaid iss my honesst besst esstimate. If you do not trusst my viewss, let uss wake girl-child friend, ass sshe alsso knowss more of sscience than you. No offence. And becausse I have told you of sstar lifting, that you clearly knew not of, at thiss time when it matterss mosst - conssider the sserioussnesss of your error if I had tried esscaping - you will protect and honor deputy sschoolmissstresss, with the undersstanding that your reign hass already begun. Now what iss the resst of the prophecy?"

Harry puts it together mainly from clues in the three most recent chapters and Chapter 86.

Edited to add: if you're reading this, Eliezer, please see this comment below for the Appendix.

In a sense, the story as of chapter 113 is an easier task than a standard AI box experiment, because HarryPrime has so many advantages over a human trying to play an AI trying to get out of a box.

Almost this exact scenario was discussed here, except without all the advantages that HarryPrime has.

1) He has parseltongue, so the listener is required to believe the literal meaning of everything he says, rather than discounting it as plausible lies. So much advantage here!

2) Voldemort put the equivalent of the "the AI in the box" next to a nearby time machine! Any predictable path that pulls a future HarryPrime into the present, saving present HarryPrime, and causing him to have the ability to go back in time and save himself, will happen. He could have time turned to some time before the binding, and not intervened because his future version is already HarryPrime and approves of HarryPrime coming into existence so HarryPrime can fulfill HarryPrime's goals.

Now that this has happened, HarryPrime, in the moment of his creation, can establish any mental intent that puts him into alignment with HarryPrime's larger outcome. There are limits, as there were when he escaped from being trapped in a locked room after Draco cast Gom Jabbar on him, by forming an intent to time travel and ask for rescuers to arrive just after his intent was formed.

The chronology has to be consistent, but there's a lot of play here.

3) HarryPrime has been unbreakably bound to a task that the binder believes is good by a method the binder thinks he understands.

In a normal "ai box experiment" the gatekeeper hasn't actually built the actual motivational structures of an actual AI. Instead, both humans are just pretending that the "boxed person" is really an AI and really has some or another goal, but they might be pretending differently. Thus, the person role-playing the AI can take very little for granted about what the gatekeeper things about "the AI's" background intent and structure.

The only reason Voldemort has to distrust Harry is the prophesy.

The only "play" in the binding is that Voldemort seems to have chosen HarryPrime's "supergoal content" poorly, so it probably doesn't have the implications that Voldemort thinks it has, though this will only become apparent after several iterations.

HarryPrime is not dumb, and not especially ethical, so until he believes that Voldemort can no longer see the unanticipated implications of his actual request, he will seem to be pursuing the goals Voldemort should have asked for.

4) Voldemort (like an idiot, again after the previous failure to test the horcrux spells) has probably has never performed this sort of spell before, and probably doesn't know what its likely psychological effects will be. He has probably never seen an implacably goal seeking agent before.

Humans, so far as I can tell, are mostly not implacably goal seeking. We wander around in action space, pursuing many competing "goals" that are really mostly tastes that evolution has given us, and role-based scripts we've picked up from ambient culture. We make complex tradeoffs between subjectively incommensurable things and make some forward progress, but much less than is theoretically possible for an effective and single mindedly strategic person.

HarryPrime has an unbreakable vow stripping away all these dithering tendencies. Thus HarryPrime, though probably abhuman at this point, should be able to conceal his abhumanity with relative ease, relying on Voldemort to treat him like a normal human with normal human motivational structures.

Voldemort is already making this error in using threat of torture of Harry's parents to goad HarryPrime into telling Voldemort about "the power he knows not".

I'm pretty sure that HarryPrime now only fundamentally cares about the torture of his parents to the degree that his unbreakable vow let's him fall back on what his earlier self, and Hermione, would recommend or care about, and that clause only triggers when HarryPrime's plans for world saving are themselves somewhat risky.

5) Harry has a huge amount of shared context and it recently contained a request for advice.

If you can think of any trick that I have missed in being sure that Harry Potter's threat is ended, speak now and I shall reward you handsomely... speak now, in Merlin's name!"

One thing HarryPrime could try is to suggest more ways to restrict himself, that to a normal human would be motivationally horrifying but to HarryPrime are still consistent with his new goal, and proves to Voldemort that he has mostly won already and killing Harry isn't that critical.

Off the top of my head, a sneaky thing Harry might suggest is converting some of the death eaters into guards against Harry's possible resurrection forever... using wording that will indirectly cause them also become x-risk mitigation robots as well.

6) Unlike an AI in the box, Harry is already out of the box in some deep senses. Aside from the time turner, he already has the power to expect anything he wants to expect of Dementors, and thereby cause them to act that way. No wand required.

The only barrier to this is that between him expecting the Dementors to do something and them actually doing it, there will be a period of time where he needs to stay alive, and while he is alive but held at wand-point he might be asked "have you betrayed me yet?" and have to admit that he had, and be killed.

All through chapter 112 Harry's mental state was unprobed and Voldemort was distracted by the costs of arranging the Death Eaters and motivating them to help make and understand the vows and so on. The only time Harry's mind was described by the narrator was during the casting of the unbreakable vow itself, to describe how a new "subscripted should" have come to exist in Harry's brain. All of Chapter 113 seems like a lot of time for some mentally generated effects to have been put in motion.

7) He is a wizard with a wand. All the partial transfiguration stuff other people have mentioned is also relevant :-)

(Edited to remove less interesting solutions)

• Harry can tell Voldemort that Harry's death has an unknown chance of hijacking Voldemort's horcrux network, and neither of them have enough information to push that probability below 5%. As far as I can tell, that's simply true. We know that Voldemort hasn't done any tests of the improved horcrux spell until now, and has been mistaken before about its working. The Voldemort described in this chapter would not accept a 5% risk on this particular plan, so he will carry out some experimental tests before killing Harry. That seems to allow Harry to evade immediate death, which is what Eliezer asked for.

• Harry's death burst will very likely interact with Voldemort's magic anyway, like the wards Voldemort placed around the spot, or the dark marks on minions' hands. That changes the whole plan. Now Voldemort must get himself and the minions far away at the moment of Harry's death, and also lift the wards. That buys some time as well, and is compatible with the previous idea.

• Voldemort has just taught Harry how to un-transfigure stuff wandlessly. If Harry's glasses are some sort of transfigured distraction that could be used to buy a couple seconds, Harry could use it, and immediately fire Flitwick's swerving hex. I'm pretty sure Voldemort doesn't know about that one, can't dodge because the hex was fast enough to drop Moody, and can't shield because that would count as magic touching. (Moreover, even if Voldemort dodges, the hex might still touch his wards around the graveyard, so maybe Harry can just fire in a random direction.) That could be one way to cause a resonance cascade, what happens next is anyone's guess.

ETA: I just posted a more fleshed out solution on /r/hpmor. It's very likely that it can be improved even further.

Is Voldemort familiar with logical syllogisms? If not, it should be possible for Harry to trick him by saying something that seems to imply something else, without actually confirming the second thing as true, a la Chapter 49:

Harry kept his face steady. "I was looking up some facts about the Patronus Charm earlier," he said. "According to The Patronus Charm: Wizards Who Could and Couldn't, it turns out that Godric couldn't and Salazar could. I was surprised, so I looked up the reference, in Four Lives of Power. And then I discovered that Salazar Slytherin could supposedly talk to snakes." (Temporal sequence wasn't the same as causation, it wasn't Harry's fault if Professor Quirrell missed that.) "Further research turned up an old story about a mother goddess type who could talk to flying squirrels. I was a bit worried about the prospect of eating something that could talk." (emphasis mine)

One possible example proposed in a review on fanfiction.net (and the one that set me on this train of thought in the first place) is, "If you kill me, the world will end." Since the world will end no matter what, the consequent is guaranteed true, making the content of the antecedent irrelevant due to contrapositive shenanigans... but Voldemort doesn't know that, and it sounds like the end of the world is dependent on Harry's death.

I have noticed many descriptors of the time, sky and moon in the story recently. I think they might be a clue.

At the Quidditch match:

• "June in Scotland meant plenty of daylight; sunset wasn't until ten."

• "As the sun set and Harry started using Lumos to read his books"

• "And as the stars began to come out"

• "Harry glanced at his watch - eleven-oh-four at night. Harry was now reading a sixth-year Transfiguration textbook; or rather he'd weighted the book open, illuminated by a Muggle glowstick,"

At the graveyard:

• "The moon above was over three-quarters full, already seeming bright with night not fully fallen."

• "gleaming darkly beneath the fading twilight sky"

• "A tall form rested upon the altar, and even in the dimming twilight it looked too pale."

• "Red eyes gleamed beneath the fading twilight,"

• "on a twilight-lit stone altar."

• "The twilight sky had dimmed further"

• "but the moonlight was too faint for certainty"

• "Harry saw by the moonlight that they all now lay in another heap by the altar"

• "The gibbous moon riding higher in the cloudless sky, the stars and wash of the Milky Way visible in all their majesty within the darkness"

If it is fully dark, it must be well past 10pm, as the text says the sun sets at 10pm. Harry left the quidditch match shortly after 11.04pm to prepare for his quest, so he could be missed or quidditch-disrupting-events could happen any time after that. Despite this, we are assured the cavalry is not coming. If it were past 11pm, what else would have to be true to know that the cavalry isn't coming?

So I did some research.

Moonlight chart

Definitions of 'shades' of twilight as shown in chart

To my surprise, my research indicates that the night never gets to 'astronomical twilight' in Scotland on the night of June 13-14. The sun sets for several hours, but doesn't go more than 12 degrees below the horizon. The sun needs to go more than 18 degrees below the horizon for the silhouette of the horizon to disappear and to be able to see the fainter stars with the naked eye.

Given all the focus on images of the stars in this story, I expect Harry, Voldemort and Eliezer to notice the difference between "the stars and wash of the Milky Way visible in all their majesty within the darkness" and the dimmer stars being missing because it is not dark enough. What does this indicate?

Are they not in Scotland? Are they not in June? Is that the real sky? Are they playing out some astronomy fan's wish fulfillment in the mirror? (Harry is already very confused that Hermione was resurrected.)

Harry's interest in astronomy enables him to notice that it shouldn't be this dark - it won't have been for some days or weeks now. Can he test any of the above without getting in too much more trouble?

This may also be a genuine mistake, my reading too much into things, a spell Voldemort cast for the ambience, or something else, but I thought it worth considering. Any thoughts?

Beneath the moonlight glints a tiny fragment of silver, a fraction of a line... (black robes, falling) ...blood spills out in litres, and someone screams a word.

I'm relatively confident that this quote is a part of the solution. Maybe Harry partially transfigures a monofilament blade and starts cutting down everything.

Interesting, so it all comes down to a version of the AI box experiment.

Dear Eliezer,

For the best experience, if you have not already been following Internet conversations about recent chapters, I suggest not doing so, trying to complete this exam on your own. . . .

Although you've requested an individual exam format, two mathematicians aren't "the same smart" as the smartest of the two of them.

The Polymath Project got off to a slow start. . . Jozsef Solymosi from the University of British Columbia posted a comment. . . over the next 37 days, 27 people wrote 800 mathematical comments. . . Just 37 days after the project began Gowers announced that he was confident the polymaths had solved not just his original problem, but a harder problem that included the original as a special case. Link

You spend many chapters teaching Harry the importance of collaboration.

"Anyhow," Hermione said. "Captains Goldstein and Weasley, you're on duty for thinking up strategic ideas for our next battle. Captains Macmillan and Susan - sorry, I mean Macmillan and Bones - try to come up with some tactics we can use, also any training you think we should try. Oh, and congratulations on your marching song, Captain Goldstein, I think it was a big plus for esprit de corps."

So I'm afraid I urge everyone to do the opposite of what you've suggested and collaborate. Sorry.

(Plausible) Harry can stall for time by explaining his discovery of Mendelian magical inheritance, and the implication that magic is not a property of Wizards but rather bestowed upon them, possibly by the Atlantean Matrix lords. This is a power, or at least knowledge, the Dark Lord knows not, and it gives him time to do his Partial Transfiguration attack, while also not giving Voldemort any kind of immediate strategic advantage.

(Implausible) This would then segue into a discussion of whether Voldemort is just seeing his CEV, and simulated-Harry trying to break it. Somehow, they end up breaking the Mirror's illusion, thus destroying this "world".

I made a countdown timer.

I've seen it on a couple of other comment threads, but I think that Harry's understanding of time-causality is key here. If the lesson of the Comed-Tea is learned, it seems that efforts to defy prophecy are useless from the get-go.

But then I'm not practiced at arguing time-travel mechanics - can anyone else elaborate on this question?

I expect that the collective effect of 'everyone with more urgent life issues stays out of the effort' shifts the probabilities very little

Perhaps, but it shifts the ability of some of us to participate much more.

We've been waiting months for the latest round of chapters - giving the "final" a couple of weeks would have been more fun for me.

For the best experience, if you have not already been following Internet conversations about recent chapters, I suggest not doing so, trying to complete this exam on your own, not looking at other reviews, and waiting for Ch. 114 to see how you did.

If we wish to win, and not merely play the role of students getting a grade, we will of course collaborate.

It's strange how the student role seems to last and last and last beyond school. I see people doing it at work all the time. Though it's hard to blame them, in an institutional culture where others see your grade on the quiz as more important than getting things done. It's really odd being somewhere that asking someone who knows is considered cheating on your quiz, instead of being productive.

EY has previously stated that HJPEV is only knows some of the content of the Sequences, because if he knew all of it he'd be too powerful to write an interesting story around. EY has also stated that Harry is now allowed to come into his full power as a rationalist, presumably meaning he can deduce anything remaining in the Sequences.

So, what things are in the Sequences that Harry hasn't yet invoked? The answer may lie there.

Important: QQ's earlier parseltongue-spoken plans for Harry to become ruler of the world were said before he heard the 'tear apart the stars' prophecy. So it appears V changed his mind after hearing the prophecy.

After 5 minutes of thinking about it, the only thing I could come up with concerns:

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

Bellatrix and Sirius are stars, and also Death Eaters. Voldemort has already torn apart Bellatrix to use the Dark Mark, and Harry can tear apart Sirius with the Partial Transfiguration trick people are talking about. How do we know Sirius is present? Because there is a Death Eater named "Mr Grim" who is stated to have known the Potters.

Hang on, isn't Sirius in Azkaban?

"I'm not serious, I'm not serious, I'm not serious..."

The "he" refers to both Tom Riddles, as they are branches of the same person.

Troubles with this suggestion:

The "HE IS THE END OF THE WORLD" part remains unresolved.

Narratively unsatisfying.

One bit of information that I haven't seen anyone bring up before, is about the original prophecy (the Harry vs. Voldemort one).

Voldemort claims it is already fulfilled. But in an earlier chapter Snape claims that as the one for whom the original prophecy was meant, he will know when it is fulfilled, and it hasn't yet. So assuming Snape isn't either lying or mistaken (and Dumbledore is also present, bringing down the chance of Snape being mistaken), then that particular prophecy is still in effect.

Snape makes another very important claim in that passage. He claims that the 'Power the dark lord knows not' is not just a power that the Dark Lord doesn't know, but one he can't know. He explicitly rules out Harry's knowledge of muggle science as this power.

As far as I can tell, this pretty much leaves 3 candidates for "Power the dark lord knows not" - Love, as per canon. Unlikely since it hasn't been brought up, and unlike in canon probably doesn't have any special powers. - Partial transfiguration. Not sure thought if this is a power that the dark lord can't learn. Presumable if he studied muggle science enough, he'd be able to learn it - The patronus 2.0 & dementor scaring ability. This is absolutely a power Voldemort will never be able to learn, and thus in my book the best candidate. Assuming of course Snape isn't full of shit.

I don't see any immediate way to translate this bit of information into an action to escape Harry's predicament. But hopefully others can do something with this. It's probably relevant, and nobody seems to be talking about it. Especially since the prophecy implies that 'the power the dark lord knows not' is key to defeating him.

Harry is allowed to solve this problem any way YOU would solve it. If you can tell me exactly how to do something, Harry is allowed to think of it.

This is not quite phrased correctly. While I know less magic than the protagonist (having not attended Hogwarts for a year), I know far more physics and mathematics than he does. I am also privy to world-building knowledge that he isn't. For example, we know about major artefacts:

• The Elder wand has been repeatedly featured in the fic, but neither Harry!Riddle not Voldemort!Riddle are aware of it yet.

We also know little trivia:

• Tom Riddle's middle name in this AU is Morfin, not Marvolo. Knowing canon this tells us something about Merope Gaunt's relationship with her father and brother.

In conclusion: it's not enough for us to think of a solution, we also need to explain how Harry can think of it. There's no point in simulating Harry's smarts on my hardware, I can use my own smarts. But I do need to simulate Harry's knowledge.

Can we each propose a non-transfiguration solution? Even if it's just a rough idea. I feel like we're getting stuck on transfiguration, and a bunch of those require very precise handling of things 10 feet away (such as death eaters) or significantly big things (Harry's body parts). Hermione struggled to get the stunning hex right on the first try, and I feel Eliezer will categorize "transfigure this very precise, remote thing" as a "new magical power".

Haven't seen this solution elsewhere: I think it's actually strong on its own terms, but doubt it's what Eliezer wants (I'm 90% sure it's about AI boxing, exploiting the reliability granted by Unbreakable Vows and parsetongue)

However, this being said, I think Harry could avoid imminent death by pointing out that if a prophecy says he'll destroy the world, then he presumably can't do that dead. Given that we have strong reasons to think prophecies can't be avoided, this doesn't mean killing him is safe, but the opposite - what Voldemort should do is make him immortal. Then the point at which he destroys the world can be delayed indefinitely. Most likely to a point when Voldemort gets bored and wants to die, after the heat death of the universe.

This isn't a great solution for Harry, because the best way to keep him alive would be paralysed/imprisoned in some fairly extreme way. But it should hit the criteria. The one really big point against it is that all this info is very available to Voldemort, so not sure why he hasn't come up with it himself.

Posting write-only. EDIT I am no longer write-only

Recall Harry's transfiguration power:

Last week, when the graduating Ravenclaws were discussing their N.E.W.T. scores, Harry had overheard that upper-year Transfiguration practice involved several 'shaping exercises' that relied more on control and precise thinking than raw power; and Harry had promptly set out to learn those, whacking himself hard on the forehead for not trying to read all the later-year textbooks earlier. Professor McGonagall had approved Harry doing a shaping exercise that involved controlling the way in which a Transfiguring object approached its final form - for example, Transfiguring a quill so that the shaft grew out first, then the barbs. Harry was doing an analogous exercise with pencils, growing out the lead first, then surrounding it with wood and finally having the eraser form on top. As Harry had suspected, focusing his attention and magic into a particular part of the pencil's ongoing transformation had proven similar to the mental discipline used in partial Transfiguration - which could indeed have been used to fake the same effect, by partially Transfiguring only the outer layers of the object. This way was proving relatively easier, though.

With this Harry can:

• Partially transfigure his leg into a winding worm. With this leg-worm he could:
  • Touch his transfigured self to Voldemort's magic, thereby causing Voldemort to collapse.
  • Seek out the time-turner . Since the leg is part of his body, twising the time turner would make him go back in time. This is a win, if none of the Death Eaters have cast anti time-turner charms, and Voldemort hasn't either. The death eaters haven't had much time and were immediately given orders. It is unclear if Voldemort would cast wards that could interact with Harry.
• Transfigure all of himself into the adult form of Voldemort and give counter orders. "That's Mad-eye Moody, you nitwits!"
• Partially transfigure his nose to cover his mouth, then cast non-wordless spells

Dumbledore can cast the Patronus wordlessly (chapter 57). Maybe Harry can too, and

• will the Patronus to cover his body (as seen in chapter 100)
• will the Patronus to charge Voldemort
• will the Patronus to Hug Voldemort, changing his utility function with the unknown power...of love!

Of course, there are lots of solutions if you allow Harry to have done stuff off-camera. "Cedric, if I don't meet you at 11:59 tonight carrying a mayonnaise-infused gerbil, please use your time turner to cause a paradox". Harry could turn into his hitherto unseen animagus form ETA which might be a peregrine falcon, the fastest of birds.

And the rest of you, you must fire if Harry Potter tries to run, even if it means striking at your fellow Death Eaters.

Useful

Harry can test the limits of Parseltongue's truth detection properties. "I am plugged in to your Horcrux network and will not be stopped by killing me now."

IMPORTANT:

This is your final exam.

You have 60 hours.

Your solution must at least allow Harry to evade immediate death, despite being naked, holding only his wand, facing 36 Death Eaters plus the fully resurrected Lord Voldemort.

If a viable solution is posted before *12:01AM Pacific Time* (8:01AM UTC) on Tuesday, March 2nd, 2015, the story will continue.

Otherwise you will get a shorter and sadder ending.

There are more details and suggestions at the end of the chapter.

Question for Eliezer: Would a post to a LessWrong HPMOR discussion thread count as a solution, or must all solutions be posted to fanfiction.net?

Here is my stab at a solution (already posted at ffnet):

First Harry tells V. that Dementors are death, Patronuses work by not thinking about death and the true Patronus works by using a diferent mindstate which V. probably cannot attain (without specifics). Second Harry states that as long as Dementors are around every person including V have in each moment a small but finite probability to be kissed by one. Over an indefinite timeframe the aggregate probaility that V. is kissed approaches one. How this would interact with V's Horkruxes is unclear but he may easily suffer a fate worse than death. Therfore he should keep Harry around at least until the dementors are dealt with.

Then he points out that given what he knows about the ambiguity of prophecies the prophecy V. heard has probably not clearly identified that Harry and not V. is the threat. Thus V. killing Harry might easily doom the world. This is especially likely as V. is not bound by the vow. Thus V. should keep Harry around to guard against his own mistakes and probably take a similar vow. He himself may offer more vows to further Vs goals in exchange for V. vowing to further Harry's goals and so on. This should be beneficial for even a purely selfish V. who wants the world to survive.

In case V. is not convinced by his above offer of cooperation Harry uses the time they are talking to prepare for an attack on V. and the Death Eaters using partial transfiguration: Thinking about venues for attack he first thinks about transfiguring an invisible nanoweapon such as a monofilament knife to decapitate the death eaters. Though he quickly realizes that that will not work since no known material including carbonanotubes is stiff enough to form an invisible blade of several meters length. Independently acting nanobots are out too, because he lacks time and knoledge to design one let alone test them for safety and efficiency. Then he realizes he does not need them, because partial transfiguration can do everything a nanobot could and even more.

He points his wand to a patch of skin on his leg and starts to transfigure the stratum corneum. An invisible bundle of carbonanotubes extends from his skin to the ground branches out to each death eater running up their robes and into their necks. (They do not feel this, since the bundle of tubes has a crossection of only 50 nm. Pain or touch receptors would not pick that up.) Another branch extends to the Dark Lord, but Harry does not dare touch him with his construct fearing the resonance. Instead he builds a small tower form the ground using carbonanotubes in a pattern resembling the Eiffel Tower extending right into the muzzle of his gun (Beneath the moonlight glints a tiny fragment of silver, a fraction of a line...). He seals the muzzle with a thin sheet of carbonanotubes and fills the barrel with nitroglycerine contained by a second thin sheet of carbonanotubes just before the bullet. All of this is very low volume and quickly transfigured.

If the Dark Lord refuses cooperation he snaps his fingers and immeadetly extends the tube in each of the death eaters neck to severe the brainstem from the spinal cord, the language center from the brain (to prevent wordless, wandless magic) and the neck from the body (black robes, falling). To make sure that everything is properly seperated he turns his entire construct (except for the part in Vs gun) into pressurised air (...blood spills out in litres,...). Now the Dark Lord either surenders or fires his gun. ...and Harry screams a word: "rennervate" and points at Hermione to wake her up. Hermione stunns V. Even if V. fired he should not die immeadetly except if part of the gun passed through his brain. Hermione transfigures V. into a small stone to prevent him from dying and thus from coming back. Afterwards they transfigure the Death Eaters for eventual revival.

I wrote multiple redundant plans, because I genuinely think Harry should be able to convince V. to cooperate for purely selfish reasons. But even if V. is not only rational and selfish but "For the Evulz" Evil and thus refuses, the transfiguration attack should secure Harrys victory.

Another possible solution path:

"There iss already in motion a power which will desstroy world if left unchecked. [entropy] If you kill me, trap me, incapacitate me, or otherwisse hinder me, I will be unable to take necesssary possitive actionss to try to sstop it and ssave world. Am sstill bound by vowss, will not take any action I think will make desstruction worsse or more likely."

Harry could start by saying "Not sssure if I should ssspeak. Mussst asssk friend firssst." He will won at least fime, at best an ally.

I can think of a solution, but may not be the solution because it relies on untested extensions of previous mechanisms having to do with "Dementers" which HarryPrime knows to be magical incarnations of death, that obey people's expectations about death. Critically, it depends on how much play he has in the distance and plasticity of dementer control.

My plan probably requires him to have put it into motion during the text we already read. Imagine that when he was surrounded at the end of chapter 112 at this moment, he put his plan into motion:

You know, said the last voice within Harry, the voice of hope, I think this is getting pretty bad even by my standards.

Right after that, he could have started expecting 40 dementers to arrive at his location without disturbing or being seen by anyone while traveling, so it doesn't change anything already known about the world before he time turned already.

He expects them to arrive in a group, and to kill everyone but him and Hermione, even if he himself has already been killed (this last clause might not work, depending on how the magic about dementer expectation control works). He expects the dementers to travel at a poetically appropriate speed (to help make the expectations plausible enough to happen), so perhaps the speed of a killing curse, which might be approximated by the speed of sound, or ~750 miles per hour.

If Azkaban is 100 miles away (doubtful) they take 8 minutes. If 200 miles (plausible), then 16 minutes. If 300 miles (also possible) then 24 minutes. I think 250 is most reasonable, so 20 minutes is the maximum likelihood for the arrival time? Unless killing curses move faster than sound, in which case earlier?

Azkaban is somewhere "unplottable" in the north sea so a 20 minute delay is reasonable. For strategic reasons, Harry expects the dementers to rendevous at a point far enough away from where he is that Voldemort and the death eaters can't sense the doom aura of the dementers. Then when 40 are ready in a group somewhere moderately close, he expects them to swoop together in at the speed of killing curses and kill everyone but him and Hermione. One for each death eater, and the spares for Voldemort.

To expect this, and expect that it had a good chance of working was a risk, requiring ~20 minutes to pass between starting the expectation and the dementers arriving, but all through chapter 113 he was not asked by Voldemort if he had betrayed Voldemort yet (this probably would count as that), so the risk has already paid off so far...

That chapter, but the way, took approximately 15 minutes and 30 seconds to occur. I read the verbal parts out loud to myself and timed how long it took.

There were bits like this where I generally assumed that it would be perceived as less than a minute (I counted 30 seconds for this line, rather than 60):

Mr. White screamed through his mask's distortion for what seemed like a full minute.

If my timing of chapter 113 count is accurate, then starting at the beginning of chapter 114 Harry needs to buy about 4 minutes and 30 seconds of conversation, and then he should expect his enemies to be attacked by dementers at an unusually fast speed.

One potential flaw in the plan is that he may not have started expecting the right things early enough. In chapter 113 this bit of narrator description of Harry's mental state shows up around the 11 minute mark and seems uncharacteristic for someone who expects dementers to show up as expected.

Harry was chilled, and shivering, and not only because he was naked in the night. He didn't understand why Voldemort was not just killing him. There seemed to be only a single line leading into the future, and it was Voldemort's chosen line, and Harry did not know what came after this.

So maybe he grew a spine and a brain right after that, in which case he started expecting dementers 4.5 minutes before the end of 113 and needs to buy more like 15.5 minutes in chapter 114.

So what does he do to buy time? Basically, he starts saying a lot of things that are true and interesting and require responses...

For each unknown power you tell me how to masster, or other ssecret you tell me that I desire to know, you may name one more of thosse to insstead be protected and honored under my reign.

Personally, I think Harry is actually HarryPrime now, and he doesn't care nearly as much about his family and friends as Voldemort thinks, at least not compared to preventing the end of the world.

So I think Harry's first move should be to think for as long as he can get away with. Then say out loud that he can think of five things off the top of his head that might be a power-known-not or other qualifying secret. This buys him time to emit more sentences and come up with more things.

(Things he could say that would make the claim of 5 reasonable include: the secret of patronus 2.0, the secret of dementers, flitwick's tourament curse, partial transfiguration, and the fact that magic is a homozygous recessive trait. But he doesn't list them right off the bat that shortly.)

After stating a number, I think he asks clarifying questions about what counts as a secret, or a power, and offers one thing that might count or might not, which would the idea of setting death eaters under other unbreakable vows (to themselves persist in the prevention of the end of the world after Harry is dead) as an example of a strategically helpful thing Voldemort might not have considered as a possible life saving thing to talk about (this also, btw potentially creates allies for HarryPrime's real new goal which is to prevent the world's destruction without stopping to be nice or fulfill other ideals).

Through his wording, he can honestly communicates that his new life goal, by the way, has in fact been transformed by the unbreakable vow that was just taken and he offers himself in service to Voldemort, conditional on Voldemort wanting to protect the world. He really wants to help.

Also it creates a potential conversational opening for him to say that in pursuit of protection of the world he actually cares more now about learn the wording of the prophesy that relates to the potential end of the world, so that he can be more effective in his world saving. Learning the prophesy is probably related to his new vowed goal.

If Voldemort is unhappy with stalling, and Harry has to get down to brass tacks fast, he let's Voldemort know that the secret of Dementers is one that he has composed a riddle for, for someone else (which he has already done for Hermione so it is in theory possible even though we haven't seen the contents of this riddle on camera yet), but it relies on insights and perspectives that Voldemort might not have and so he needs to ask some questions to restructure the riddle. But doing so could take a while and could be done after other secrets were exchanged for lives. Which order does Voldemort prefer?

If Voldemort wants a patronus 2.0 riddle that is optimized for him, then there are a bunch of potentially relevant things about Voldemort's mind and plans that determine whether and how to construct a riddle personalized to him, like "Can you cast patronus 1.0 and if not, why do you think not?"

It is hard to plan a conversation in detail, because the other person's reactions are always relevant, but I could relatively easily see Harry stretching out a conversation about secrets for a good 20-60 minutes, and somewhere in that conversation, hopefully, the dementers swoop in and maybe kill everyone but Harry and Hermione, or at least it gives Harry a distraction during which he might grab the time turner and escape.

I'd rather get the longer happier ending (though I am curious about the shorter sadder ending). Should I submit this plan to fanfiction as a possible solution, or does it need more polishing?

Oh, interesting. EY just asked his readers to solve an impossible problem. I wonder how many will feel they have enough at stake here to actually pay the mental and emotional tax involved in solving impossible problems, to maintain that awful tension. I mean, at the end of the day, it's a fanfic on the Internet.

I sure hope the problem looks easier to some smarter readers than me, because it's gonna be silly from a promotion-of-rationality angle if the addition of rationality to Harry Potter changes the outcome from "hero wins" to "hero dies and people he cares about get horribly tortured to death".

Planning thread over at /r/HPMOR for centralized discussion. It's probably better to have segregated groups working on this, but I don't really think that'll be a problem.

We know that previous attempts by Voldemort to thwart a prophecy have backfired horribly. It therefore seems reasonable to assume that prophecies in HPMoR (as in canon) are self-fulfilling. (Warning: TVTropes-link!)

I therefore predict that Voldemort’s efforts to thwart this prophecy will counteract that intention and lead to the fulfillment of that same prophecy.

The Parseltongue statement must be a critical part of the upcoming solution, I think. Simply killing the Death Eaters will not do; they are, as Voldemort puts it, useless. (That is, a solution that disables the Death Eaters but not Voldemort is not a solution.)

The text of the boundary conditions suggests that Harry can't change Voldemort's values, but the lesson suggestion makes clear that he can change Voldemort's beliefs.

I think the first thing for Harry to suggest is that the prophecy is being misinterpreted. The trouble with this is he needs to hear the prophecy to argue it as well as possible, and Voldemort is unlikely to tell it to him.

So, what lessons does Harry have for Voldemort? Partial transfiguration, and implicitly timeless physics. Friendship? Science fiction? Dyson spheres? We, with knowledge of the prophecy, can feed Voldemort the data he needs to come to the right conclusion.

(During these discussions, of course, he can be partially transfiguring whatever he likes. Carbon nanotubes, hollowing out the ground beneath him, and so on.)

Not a solution, but should the Death Eaters be discounted as not good for much of anything?

I don't just mean that Voldemort has shown them to be fairly incompetent, but that they may be too shaky to use whatever remains of their skills.

As an orthodox Discordian, I would be very pleased if it turned out that one of the Death Eaters has an idea which would be very useful for Voldemort, but is too afraid to say it.

(Not a serious suggestion)

Using the Axiom of Choice and partial transfiguration, Harry divides himself into two exact copies, one of which is killed by the Death Eaters and the other of which escapes.

Observation: If the purpose of this exercise is to run an AI box experiment, with EY as gatekeeper and the internet hivemind as the AI, then the ability to speak in parseltongue is problematic: It appears to make the game easier for the AI, thereby preventing the results from being generalized to a standard AI box experiment.

So why did Eliezer include the parseltongue constraint?

Maybe parseltongue is meant to introduce the concept of provability in a way that everyone can understand. To speak in parseltongue in real life, you just speak in logic statements and supply a proof with any statement you make. It seems reasonable (modulo computational complexity and provability concerns) for an AI to be able and/or required to supply proofs in an AI box experiment and parseltongue enables that in version of the game in the story.

I don't understand the constraint to speak only in parseltongue. Is that there to force us to focus on a solution set that is somehow of interest for friendly AI research?

Harry obviousely needs to buy some time, so he'd better start speaking. Patronus V2.0 grants only the "good" kind of power and feeds on caster's maxHP, so it could be revealed easier than partial transfiguration. Some meaningful amount of time is going to be acquired (while explaining HPJEV's viewpoint) that way, because HPJEV and LV oppose death in entirely different ways (one wants to fight it and the other one flees). But that's too easy and either is not in the solution at all or is followed but something more clever.

By the way, nobody said that that quote about falling black robes was from the good ending. Nor we have a 100% proof that Patronus V2.0 blocks any AK: it could be only LV's AK, due to resonance.

Also, assuming that both HPJEV and Hermione survive with their memories intact and have a chance to talk, it's going to be very awkward. Being murdered by LV can be expected, at least, but it's not easy at all to tell Hermione that she has just been brutally resurrected with at least three Dark rituals, has her mind state constantly backed up to a Dark item and regereneration ability similar to the one of the weapon which killed her in the first place.

Just finished reading. Wow! This story is so bleak. I suspect Voldemort just "identity raped" Harry into becoming an Unfriendly Intelligence? Or at least a grossly grossly suboptimal one. Harry himself seems to be dead.

I'm going to call him HarryPrime now, because I think the mind contained in Riddle2/Harry's body before and after this horror was perpetrated should probably not be modeled as "the same person" as just prior to it.

HarryPrime is based on Harry (sort of like an uploaded and modified human simulation is based on a human) but not the same, because he has been imbued with a mission that he must implacably pursue, that has Harry's identity (and that of the still unconscious(!) and never interviewed(!) Hermione) woven into it as part of its motivational structure, in a sort of twist on coherent extraplotated volition.

"if we knew more, thought faster, were more the people we wished we were, had grown up farther together"

Versus how "old Harry" and "revived Hermione" were "#included" into the motivational structure of HarryPrime:

Unless this very Vow itself is somehow leading into the destruction of the world, in which case, Harry Potter, you must ignore it in that particular regard. You will not trust yourself alone in making such a determination, you must confide honestly and fully in your trusted friend, and see if that one agrees. Such is this Vow's meaning and intent. It forces only such acts as Harry Potter might choose himself, having learned that he is a prophesied instrument of destruction.

My estimate of Voldemort's intelligence just dropped substantially. He is well trained and in the fullness of his power, but he isn't wise... at all. I'd been modeling him as relatively sane, because of past characterization, but I didn't predict this at all.

(There are way better ways to get a hypothetical HarryPrime to "not do things" than giving him a mission as an unstoppable risk mitigation robot. If course, prophesy means self consistent time travel is happening in the story, and self consistent time travel nearly always means that at least some characters will be emotionally or intellectually blinded to certain facts (so that they do the things that bring about the now-inevitable future) unless they are explicitly relying on self consistency to get an outcome they actively desire, so I guess Voldemort's foolishness is artistically forgivable :-P

Also, still going meta on the story, this is a kind of beautiful way to "spend" the series... bringing it back to AI risk mitigation themes in such a powerfully first person way. "You [the reader identifying with the protagonist] have now been turned by magic into an X-risk mitigation robot!")

Prediction: It makes sense now why Riddle2/HarryPrime will tear apart the stars in heaven. They represent small but real risks. He has basically been identity raped into becoming a sort of Pierson's Pupeeteer (from Larry Niven's universe) on behalf of Earth rather than on behalf of himself, and in Niven's stories the puppeteer's evolved cowardice (because they evolved from herd animals, and are ruled by "the hindmost" rather than a "leader") forced them into minor planetary engineering.

As explained in Le Wik:

"In short, we found that a sun was a liability rather than an asset. We moved our world to a tenth of a light year's distance, keeping the primary only as an anchor. We needed the farming worlds and it would have been dangerous to let our world wander randomly through space. Otherwise we would not have needed a sun at all.

"We had brought suitable worlds from nearby systems, increasing our agricultural worlds to four, and setting them in a Kemplerer Rosette."

Prediction: HarryPrime's first line will be better than any in the LW thread where people talked about the one sentence ai box experiment. Eliezer read that long ago and has thought a lot about the general subject.

Something I'm still not sure about is what exactly HarryPrime will be aiming for. I think that's where Eliezer retains some play in his control over whether the ending is very short and bleak or longer and less bleak.

Voldemort kept talking about "destruction of the world" and "destroying the world" and so on. He didn't say the planet had to have to have people on it, but he might not have been talking about the planet. "The world" in normal speech often seems to mean in practice something like "the social world of the humans who are salient to us". Like in the USA people will often talk about "no one in the world does X" but there are people in other countries who do, and if someone points this out they will be accused of quibbling. Similarly, we tend to talk about "saving the earth" and it doesn't really mean the mantle or the core, it primarily means the biosphere and the economy and humans and stuff.

From my perspective, this was the key flaw of the intent:

But all Harry Potter's foolishness, all his recklessness, all his grandiose schemes and good intentions - he shall not risk them leading to disaster! He shall not gamble with the Earth's fate!

The literal text appears to be:

I shall not by any act of mine destroy the world. I shall take no chances in not destroying the world. If my hand is forced, I may take the course of lesser destruction over greater destruction unless it seems to me that this Vow itself leads to the world's end, and the friend in whom I have confided honestly [ie Hermione] agrees that this is so.

And then the errata and full intention was:

You will swear, Harry Potter, not to destroy the world, to take no risks when it comes to not destroying the world.

This Vow may not force you into any positive action, on account of that, this Vow does not force your hand to any stupidity... We must be cautious that this Vow itself does not bring that prophecy about.

We dare not let this Vow force Harry Potter to stand idly after some disaster is already set in motion by his hand, because he must take some lesser risk if he tries to stop it.

Nor must the Vow force him to choose a risk of truly vast destruction, over a certainty of lesser destruction.

But all Harry Potter's foolishness, all his recklessness, all his grandiose schemes and good intentions - he shall not risk them leading to disaster!

He shall not gamble with the Earth's fate!

No researches that might lead to catastrophe! No unbinding of seals, no opening of gates!

Unless this very Vow itself is somehow leading into the destruction of the world, in which case, Harry Potter, you must ignore it in that particular regard.

You will not trust yourself alone in making such a determination, you must confide honestly and fully in your trusted friend, and see if that one agrees.

In the shorter and sadder ending, I think it is likely that HarryPrime will escape, but not really care about people, and become an optimizing preservation agent of the mere planet. Thus Harry might escape the box and then start removing threats to the physical integrity of the earth's biosphere.

Also the "trusted friend" stuff is dangerous if Hermione doesn't wake up with a healthy normal mind. In canon, resurrection tended to create copies of what the resurrector remembered of a person, not the person themselves.

In the less sad ending I hope/think that HarryPrime will retain substantial overlap with the original Harry, Hermione will be somewhat OK, and the oath will only cause HarryPrime to be constrained in limited and reasonably positive ways. Maybe he will be risk averse. Maybe he will tear apart the stars because they represent a danger to the earth. Maybe he will exterminate every alien in the galaxy that could pose a threat to the earth. Maybe he will constrain the free will of every human on earth to not allow them to put the earth at risk... but he will still sorta be "the old Harry" while doing so.

Eliezer gave a hint of the solution in chapter 5:

"You triumphed over the Dark Lord by being more awful than he was, and survived the Killing Curse by being more terrible than Death."

Regardless of other differences in utility function, Harry and Voldemort both want the world to not be destroyed, and consider this of the utmost priority.

Aumann's agreement theorem means that as they are both rationalists, they should be able to come to the same opinion on what the best course of action is to prevent that. Harry was willing to sacrifice himself earlier to save others.

Why hasn't Voldemort suspended Harry in air? He floated himself into the air as a precaution against proximity, line of sight problems, and probably magics that require a solid substance to transmit through. If Harry were suspended in air partial transfiguration options would be vastly reduced.

Why hasn't Voldemort rendered Harry effectively blind/deaf/etc. - Harry is gaining far more information in real time than necessary for Voldemort's purposes?

Also, it seems prudent not to let Harry get all over the place by shooting him, smashing him, etc. without some form of containment. I don't know how some part of Harry could cause problems, but it seems prudent to eliminate every part of him with Fiendfyre (blood, guts, and all) if that is what Voldemort is aiming for.

Can Fawkes be summoned to extract Harry? If it helps Harry can decide to go to Azkaban.

Harry should be aware that reality is basically doomed to repeat the Atlantis mistake by now (either via AGI or whatever Atlantis unlocked). With the vow that Voldemort made him take he can honestly say that he is the best bet to avoid that fate. That is, Voldemort now needs Harry (and Hermione) to save reality. This seems like the most straight forward method get out of the current annoyance.

Some partial transfiguration options I haven't seen mentioned: - Colorless / odorless neuro toxins (Harry should have researched these as he is in 'serious mode' now that Hermione died). Delivered via the ground directly into each death eater and/or into the air in specific areas. - Nanobots - I can't recall at this time if this would work or if Harry needs to have the design already in his head. It is possible Atlantis tech. may utilize a vast array of these already. - Transfiguration may allow one to exploit quantum weirdness. Many things can happen at very small scales that could happen at large scales if everything is lined up just so (which never happens in reality, but transfiguration may make possible).

Why doesn't LV tell one of the DEs to finite incantatem HP's glasses?

If you can think of any trick that I have missed in being sure that Harry Potter's threat is ended, speak now and I shall reward you handsomely... speak now, in Merlin's name!"

Voldemort forgot a very basic ”trick”: disarming Harry first.

At the end of chapter 112, we wondered about that, too. It turns out that Harry needed to have the wand to perform the vow. With that out of the way … why does Harry still have his wand? Is this just because Eliezer wants to make sure that Harry still has a way out? Or is there some in-universe reason for Voldemort to allow this?

I regard fighting as futile (can't speak magic without death eaters attacking, can't cast worldess magic without Voldemort sensing through resonance and shooting). Harry must lose.

Voldemort is only killing him because of the prophecy. Harry should ask to hear the prophecy, so that if he is ever reborn somehow he can avoid it. Voldemort will probably tell him, hard to think how giving information about the destruction of the world to Harry could hurt it, since he's taken the Vow and now can only threaten the world through ignorance.

Once Harry hears the prophecy he can point out that there is no reason (beyond the coincidental timing) to think that he is the person referred to in it. If Voldemort agrees, and no longer NEEDS Harry's death, then Harry offers to earn his life by serving Voldemort with another Unbreakable Vow insuring his loyalty.

Harry, if not the World-Ender, would be super-valuable to Voldemort as: 1. False opposition figure to lure in and betray opponents 2. World-Safety-Vowed Science Czar in the new regime, in charge of monitoring Muggle and Wizard breakthroughs and making certain they don't interfere with the earth's new role as Voldemort's idiot-hunting range. 3. Bodyguard vs. Dementors

If Voldemort accepts, Harry goes through with this, and becomes the Dark Lord's Vowed servant, thereby surviving this crisis. As for the future? Perhaps the horse will learn to sing.

Harry needs to lose. He needs to drop his wand, kneel down, and say in Parseltongue, "I loosssse." Quirrel has already set up several tests that Harry has failed by refusing to lose. By proving that he can indeed lose, instead of continuing to escalate the conflict until the stars themselves are at risk, he may be able to pass LVs final test.

I remembered I have a PredictionBook account that I registered some years ago and forgot about, so I might as well get started with this whole "calibration" business.

The true solution will hinge on truly convincing Voldemort to let Harry out of the box (i.e. no “brute force” transfiguration solutions where talking is just a distraction): 95%

The true solution involves time travel: 50%

The true solution relies on Partial Transfiguration: 80% (this isn't in contradiction with #1 - it can involve Partial Transfiguration (e.g. as a threat, or a demonstration, or distraction), it just won't be the lynchpin of the entire plan)

Conditional on EY accepting a viable fan solution, it will be different to what will actually happen in the story: 75%

I have a way of escaping that uses an item that has been established.

A: In the interest of keeping it simple the thing the most obvious answer for something Harry can do that he in theory could teach Voldermort/keep him talking is partial transfiguration.

B: Once Harry tells Voldermort that he can partially transfigure things, Voldermort will want to know the words/motions. Harry can say that he can teach Voldermort (he can't teach him how to cast a Patronus due to Voldermort's lack of love and he can't teach him how not to fear the death the way Harry does, but Harry CAN teach Voldermort how to see the world made up of component atoms given enough time) but it would be easier to teach while doing/give him a visible example of how it works as he teaches (not a lie, it would be possible to teach without doing, but Parseltongue allows for lies of omission) this can open the door to at the very least get the orders moved from “Kill him if he tries to cast a spell” to “lets see you do it while I stand behind/off to the side/under heavy shields” while Voldermort watches Harry try to partially transfigure something, or at least keep Voldermort listening longer than the first 60 seconds, and how he reacts to the knowledge will determine what options are open to us next.

C: Once Harry brings up the point he can also suggest to Voldermort that he might want to dismiss any of the Death Eaters who he does not want to have present while Harry explains/demonstrates the nature of this power. Because while he can speak only in Parseltongue, he'll still have to be showing it off in front of everyone Voldermort wants present. Voldermort is probably much too smart to actually fall for this, and lead to him dismissing any of the Death Eaters, but spelling it out can buy Harry a few more seconds/Voldermort might decide to dismiss one or two of his followers, there is no downside to doing it.

D: Harry explains in Parseltongue that he show the power of partial transfiguration by changing the glasses he is wearing, which he will take off, and hold in one hand, while he holds the wand in the other.

E: Harry will transfigure half of the glasses into half of a playing card.

F: As soon as the transfiguration is complete and around the same time Lord Voldermort possibly starting to recognizes the king of hearts, Harry will bite down on the card with his teeth, and pull with the hand that held it, ripping it in half.

Yes I know it was said that he was supposed to have a Toe-Ring as a Harry's "Emergency Portkey", but that's helpful the same way that the Chamber on the third floor was helpful at keeping people out. It's meant to look more helpful/threatening than it really is.

Given that Harry is wearing a ring just like that one, with Hermonine's body in it instead, where is Harry's "Emergency Portkey"? Well wouldn't the perfect place to have one, be something he'd never be without, something that he'd always have within hands reach, something he could finger and caress and adjust without drawing too much attention?

Say the glasses on his face...

G: As it has not been previously established within the story what Harry has done with the playing card deck he got from “Santa Claus” it is not impossible or against the rules to suggest that Harry transfigured the king of hearts into a pair of glasses. He is saving himself via efforts that he had taken in advance that do not directly contradict anything we have previously been shown (the equivalent of an extended flashback scene in Leverage which shows far more happen than the initial version of the scene we saw for the first time)

H: Likewise it has never been ruled that a portkey looses its powers if it is transfigured into some other form than the one it had in the first place.

I: It is reasonable to assume that with his life depending upon it, Harry can tear a card apart faster than the time it will take for Voldermort to realize what is happening, give the order to attack, or cast a spell himself (even non-verbally) and have the spell cross the distance between himself and Harry, likewise he can do it fast enough that he can at least avoid being fatally shot by Voldermort.

J: As they have walked several miles they are clearly outside the grounds of Hogwarts, so its wards are not in play. Given that the Death Eaters were able to apparate to the graveyard rather than flying there on broomsticks, it is safe to assume that the graveyard had not previously been warded to prevent people from apparating to or from it before they did.

There is nothing in the story describing Voldermort or any of the others warding it afterwards. The wards that Voldermort mentions are clearly of an anti-time turning verity since he mentions the six hour limit so they'd be anti-time turner, but clearly anti-time turning can't be the same thing as anti-aparating because you can Phoenix into Azkabhan but not time turner inside it, or apparate inside it.

Likewise it is unlikely that the place was set up previously before they arrived to let you have a one way apparation (in but not out, assuming such a thing is possible with apparation we see it requires a magical artifact or a phoenix to get into Azkhaban there may be no such thing as a one way apparation ward), because magic that powerful would end up getting noticed which is what Voldermort doesn't want to happen since he needed the site of his ritual to not stand out.

So we have not had it directly spelled out that apparition and by effect portkeys can't be used to leave the garveyard and we have some fair evidence that it could be possible With that in mind, tearing up the card should cause Harry to be taken “somewhere in London”, and the old saying “Anywhere is better than here” doubtlessly applies at the moment.

K: Not only will he be somewhere else, but unless Voldermort was lying in a situation he would have no reason to lie in, and possesses powers dealing with portkey location determination that haven't shown up anywhere else in the story (nobody in cannon Potter or this Potter is shown to be able to tell where a portkey will take someone just by studying it) it is logical to assume that if Harry tears the card up, then Voldermort can not simply apparate right after Harry, and instead will have to start searching London for him.

L: While Voldermort starts to look for him Harry can cast a Patronus to get help from others, and start using partial transfiguration to make whatever materials he expects to need.

At the very least, by this point he has surely avoided “immediate death”. While meeting the following rules.

Harry must succeed via his own efforts. The cavalry is not coming. Everyone who might want to help Harry thinks he is at a Quidditch game.

This solution requires no “cavalry” the outside help Harry has been given (the king of hearts) is already well established.

Harry may only use capabilities the story has already shown him to have; he cannot develop wordless wandless Legilimency in the next 60 seconds.

Harry's ability to partially transfigure objects is well established already within this story.

Voldemort is evil and cannot be persuaded to be good; the Dark Lord's utility function cannot be changed by talking to him.

This is not an issue as the solution involves Harry escaping from Voldermort, and doing so simply by obeying his orders until the very last moment.

Harry raises his wand or speaks in anything except Parseltongue, the Death Eaters will fire on him immediately.

Harry can partially transfigure his glasses back into half a playing card without raising his wand by taking off his glasses and holding them lower to the ground, it is not unreasonable for him to also say that this skill requires intense concentration in Parseltongue (because it does) which is why he will be slightly hunched over examining the glasses very carefully as he works on them. This will have the effect of getting Harry's teeth closer to the edge of the card so he can bite and tear more quickly.

If the simplest timeline is otherwise one where Harry dies -if Harry cannot reach his Time-Turner without Time-Turned help -then the Time-Turner will not come into play.

Though time travel could without question be useful in the immediate future (for a given definition of “future”) this plan does not require any monkeying about with timelines to work, Harry can have taken this precaution at any point in time since he showed Voldermort the card itself back in chapter 65.

It is impossible to tell lies in Parseltongue.

Everything Harry needs to say in Parseltongue is truthful.

1:Harry knows how to partially transfigure.

2:Harry could teach Voldermort how to do it.

3:Voldermort should send away any Death Eaters he does not wish to see the process being done slowly and carefully before their eyes as opposed to being used quickly in battle.

4: Harry will show off the skill by partially transfiguring his glasses which he will hold in one hand, while he holds his wand in the other.

Given that there is no rule 7: “Harry is not allowed to have taken any precautions we did not see him take on screen/in writing” this by following steps A through L Harry can arrive naked “somewhere in London” naked with half of his glasses and his wand, but alive.

Can anyone see a way to improve this plan/ any obvious flaw?

Let's discuss that mirror in a bit more detail. A fantastically powerful artifact that's trying to avoid the destruction of the world shouldn't be outside discussion when you (or Voldemort) are trying to avoid the destruction of the world.

First let's get away from suggestions like "Harry should convince Voldemort they're in the mirror". If Harry believed that were true, he wouldn't want to make Voldemort aware of it because Voldemort being trapped inside the mirror is good. If Harry believed they were not in the mirror, he couldn't claim he believed they were.

But still, that mirror is mightily suspicious. At the very least, Harry might point out that this artifact could be an ally for Voldemort in reference to the particular goal of avoiding destruction of the world. The mirror seems to be at least a source of information, and Voldemort knows he lacks information about how to avoid the prophecy. Voldemort should at least make sure Harry won't cause the apocalypse by dying. The mirror needs to reflect Harry to divulge information about him, so Harry shouldn't be destroyed immediately because then the information would be lost. Instead, Harry should be brought before the mirror. (This buys another couple of minutes - so shouldn't it count as a solution?)

The obvious best way to convince Voldemort there's something about the mirror that Harry understands and he doesn't would be to supply a translation of the "Words of False Comprehension". And that certainly feels doable, there are a bunch of clues and the search space can't be that big. edit: Good discussion of this.

Beyond that, there's a blinding amount of possibilities involving that mirror. I don't see how Voldemort can be sure he isn't inside that mirror, given that he knows that he doesn't know how the mirror works exactly. Harry could suggest tests: For example, since the mirror has "all its consequences severed from Time" maybe time-turners shouldn't work inside it. (This has the advantage that testing it should take another hour.)

Voldemort is going full Bond villain and talking when he should be killing. I figure I'll have to sleep on this problem, but here are some observations:

• Harry can't speak with the Death Eaters. We haven't been told of a secret Parselmouth among them, so any conversation will be intelligible only to Harry and to Voldemort.

• Voldemort can periodically ask in Parseltongue whether Harry is doing anything to try to escape, and a refusal to answer would likely result in a swift death.

• It has been pointed out in canon that a good Legilimens can detect when someone is casting a spell (Harry vs. Snape in Half-Blood Prince). Whether wordless, wandless magic could evade Voldemort in this scenario is questionable.

• The area is warded, so Apparition, portkeys, and probably phoenix teleportation might not be usable. On the other hand, Harry is Tom Riddle. Death Eaters were able to apparate to the location, suggesting those particular wards could be bypassed. Perhaps Voldemort committed an oversight here. And Harry presumably still has that portkey Dumbledore made for him.

• Harry has a big rock whose transfiguration is bound to expire in the near future.

• Harry and Voldemort spent a long time brewing that potion. Haven't worked out a timetable but I figure Harry's got a fair chance of stalling until someone notices him gone.

• We don't know where Cedric fits in. However, involving him would basically involve us making up explanations given our knowledge of how things turn out. Absent any detail of Harry's plans regarding him, we can't have involve some secret plan between the two.

• Patronus 2.0 is the big daddy of things Voldemort doesn't know and would take a long time to understand. Partial transfiguration is another useful power Voldemort knows not. Using them could be an issue on account of the tactical situation, but Harry can certainly talk about them and possibly sell them as something Voldemort would want to take the time to learn.

At present, I figure that the best approach that doesn't involve deux ex machina (admittedly a power of canon-Harry) or details unknown to the reader would involve talking to Voldemort and trying to either buy time or pique his interest enough to delay killing Harry until a later day. Using any kind of force to resist would be extremely risky and likely futile.

Thinking about AI boxing - note that it is Harry who represents humanity, his core values and goals were not changed that much by the Vow, they were just formalized.

It is LV that has goals that are mostly what we'd agree about (`ensure the continuous existence of the world'), but he has very different values and no moral constraints. In short, dealing with him is like dealing with an Unfriendly AI or an Alien mind (like Sorting Hat).

So this is more like a clash between Unfriendly (or better, Indifferent) and a Friendly AI, where the goals are more or less compatible, but in addition the FAI keeps human values. And the UFAI got there first and is more powerful.

The rational way if your goals are compatible is to cooperate - however, Harry's values almost ensure that he will defect given the chance. And LV knows it, so the rational action for him is to defect (=kill) as well.

I shall take no chances... in not destroying the world...

Oh my... did Voldemort just magically imbued Harry to do his best to put the whole world into time-frozen stasis in the Mirror?

Though revealing this to LV would not do any good - there is a failure safe mode, namely killing Harry, and if LV learns what he did (apart from pointing out his own stupidity), he has all the motivation to kill Harry right now.

Skimming over (part of) the proposed solutions on FF.net has thoroughly destroyed any sense of kinship with the larger HPMoR readership. Darn, it was such a fuzzily warm illusion. In concordance with Yvain's latest blog post, there may be few if any general shortcuts to raising the sanity waterline.

Here is a suggestion that I haven't seen yet. I don't think it constitutes a full plan by itself, but it fits the form of an AI box experiment with Harry as the AI.

Harry and Voldemort's discussion about testing his horcrux 2.0 spell by offering immortality to one of his friends (read: minions, in his case) revealed a weakness, that Voldemort is heavily biased against certain ways of thinking. Harry should remind him of this in the context of the Patronus 2.0 spell. The fact that Harry was able to discover a new (and incredibly powerful, as we have seen) form of magic simply by having the right mindset may indicate that certain mindsets are key to discovering deeper secrets of magic as a whole. (I'm envisioning here, as may or may not be canon, magic as an API for tapping into the power of Atlantis.) Voldemort has a known interest in the deeper secrets of magic, and for this reason he should keep Harry alive, or risk losing access to mindsets he currently can't fathom.

I don't see how there could possibly be a real solution. No matter what Harry offers Voldemort -- for example even if he offers to make an Unbreakable Vow to devote himself to serving Voldemort's purposes -- Voldemort will still worry that the prophecy will mean that Harry will end up destroying the world. So he will simply kill him anyway, like an AI Gatekeeper who doesn't listen but simply says "AI DESTROYED" immediately.

But it does not serve as a solution to say, for example, "Harry should persuade Voldemort to let him out of the box" if you can't yourself figure out how.

It's a shame that nobody's going along this line of thought. It would be cool to see a full, successful AI-Box experiment out there as a fanfiction.

(I'd do it myself, but my previous attempts at such have been.... eheh. Less than successful.)

Thoughts:

• Can the unbreakable vow be leveraged for unbreakable pre commitments?
• Harry knows that the horcruxes will eventually be destroyed through heat death of the universe if nothing else and could use this to tell Voldemort something like "if you kill me you will die" in parseltongue

"Expecto Patronum", at which point Death-Eaters will fire an utterly futile barrage of AKs. Voldy still can't fire directly at Harry due to resonance. Gun is not as much concern if you move fast enough and considering Voldy is some distance away. Gives Harry enough elbow room to get to his nearby (?) Pouch, Cloak and Time-Turner with 1 more hour on it. At this point we're sorta free of any serious constraints.

Harry's assets:

• Glasses - probably a distraction, but could be just about any nonhuman object, transfigured.
• Cedric - probably in the mokeskin pouch, not easily accessible, probably only useful as a human shield, which is not Harry's style
• Invisibility cloak - might be able to block the Killing Curse, useful in general, Harry is the Master of this Deathly Hallow, it's plausible but unlikely that he'd be able to Call it without words or gestures.
• Voldemort's bargain - Voldemort has promised in Parseltongue to protect one person for each power Voldemort knows not that Harry names.
• Partial transfiguration - both a Power Voldemort Knows Not and a tactical tool
• Wand
• Harry's own flesh (which he can use for partial transfiguration)
• The air
• The death eaters (including their robes, their bones, etc.)
• Sirius ("Mr Grim")
• Stuporfy

Foreshadowing / prior hints of resources:

• Thick/heavy enough physical objects can block curses aside from the Killing Curse
• Resonance between Harry's and Voldemort's magic more likely to harm/incapacitate Voldemort than Harry
• Harry was instructed by Voldemort to cast Mahasu on any student in the classroom, chose himself. Foreshadows choosing to use promise of protection on himself?
• Antimatter was mentioned earlier, Voldemort may not know enough about it yet.
• Hermione transfigures a Buckytube
• Use of Muggle devices
• Harry's prior weakness is that he doesn't ask others for help
• Harry decided to accept the idea that the air can't be transfigured before he figured out the insight necessary to do partial transfiguration, this could be wrong, the air as well as his flesh could be transfigurable
• Prophecy about tearing apart the very stars (meaning Sirius and Bellatrix and Draco?)

Harry had to remove his left shoe, and take off the toe-ring that was his emergency portkey if someone kidnapped him and took him outside the wards of Hogwarts (and didn't put up anti-Apparition, anti-portkey, anti-phoenix, and anti-time-looping wards, which Severus had warned Harry that any inner-circle Death Eater would certainly do).

That seems to rule out apparition, portkeys, phoenixes, and time looping, so transfiguring a time turner into his hands is out, as is trying to get into a Phoenix frame of mind to summon Fawkes or another phoenix to send a message, or using his portkey.

"There are desks which are heavy enough to be fatal if dropped from a great height. There are chairs with metal legs that could impale someone if driven hard enough. The air in this classroom would be deadly by its absence, since people die in vacuum, and it can serve as a carrier for poison gases."

Harry had to stop briefly for breath, and into that pause Professor Quirrell said:

"That's three. You need ten. The rest of the class thinks that you've already used up the whole contents of the classroom."

"Ha! The floor can be removed to create a spike pit to fall into, the ceiling can be collapsed on someone, the walls can serve as raw material for Transfiguration into any number of deadly things - knives, say."

"That's six. But surely you're scraping the bottom of the barrel now?"

"I haven't even started! Just look at all the people! Having a Gryffindor attack the enemy is an ordinary use, of course -"

"I will not count that one."

"- but their blood can also be used to drown someone. Ravenclaws are known for their brains, but their internal organs could be sold on the black market for enough money to hire an assassin. Slytherins aren't just useful as assassins, they can also be thrown at sufficient velocity to crush an enemy. And Hufflepuffs, in addition to being hard workers, also contain bones that can be removed, sharpened, and used to stab someone."

By now the rest of the class was staring at Harry in some horror. Even the Slytherins looked shocked.

"That's ten, though I'm being generous in counting the Ravenclaw one. Now, for extra credit, one Quirrell point for each use of objects in this room which you have not yet named." Professor Quirrell favored Harry with a companionable smile. "The rest of your class thinks you are in trouble now, since you've named everything except the targets and you have no idea what may be done with those."

"Bah! I've named all the people, but not my robes, which can be used to suffocate an enemy if wrapped around their head enough times, or Hermione Granger's robes, which can be torn into strips and tied into a rope and used to hang someone, or Draco Malfoy's robes, which can be used to start a fire -"

"Three points," said Professor Quirrell, "no more clothing now."

"My wand can be pushed into an enemy's brain through their eye socket" and someone made a horrified, strangling sound.

"Four points, no more wands."

"My wristwatch could suffocate someone if jammed down their throat -"

"Five points, and enough."

"Hmph," Harry said. "Ten Quirrell points to one House point, right? You should have let me keep going until I'd won the House Cup, I haven't even started yet on the unaccustomed uses of everything I've got in my pockets" or the mokeskin pouch itself and he couldn't talk about the Time-Turner or the invisibility cloak but there had to be something he could say about those red spheres...

This vaguely suggests a few options:

• Harry could improvise a dark ritual to sacrifice some of his internal organs to "hire an assassin" (counting on some sort of magical healing afterwards).
• Susan Bones might also be in the pouch ("Hufflepuff [...] Bones"). Note that the real Susan Bones was not with the other students who encountered Snape in the corridor.
• Harry likely knows of some efficient poisonous gases, if he can hold his breath for long enough he can simply transfigure part of himself into one of these and wait for the Death Eaters to drop.
• Harry could somehow try to cast a spell on Voldemort to invoke the resonance, push him in a direction that disrupts the semicircle of Death Eaters.
• Harry could transfigure the air around him into a thick physical barrier that blocks everything except the Killing Curse.

Ignoring the gasps rising from behind him, Harry crossed the radius of the Patronuses, strode to a single pace from Death. Its unhindered fear burst around him like a whirlpool, like stepping next to the sucking drain of some huge bathtub emptying out its water; but with the false Patronuses no longer obscuring the level on which they interacted, Harry could reach the Dementor even as it could reach him. Harry looked straight into the pulling vacuum and -

the Earth among the stars

all his triumph at saving Hermione

someday the reality of which you are a shadow will cease to exist

Harry took all the silver emotion that fueled his Patronus Charm and shoved it at the Dementor; and expected Death's shadow to flee from him -

• and as Harry did that, he flung his hands up and shouted "BOO!"

The void retreated sharply away from Harry until it came up against the dark stone behind.

Harry can sort of wandlessly wordlessly cast something like a Patronus, he could try to do something like this to Voldemort.

Beneath the moonlight glints a tiny fragment of silver, a fraction of a line... (black robes, falling) ...blood spills out in litres, and someone screams a word.

This strongly suggests a Buckytube monofilament whipped around to decapitate all the Death Eaters. This is the most plausible solution, and it's somewhat compatible with the other Partial Transfiguration option, which is to tell Voldemort about it in exchange for protecting Harry's life (and to buy time). This is also compatible with Harry's glasses being a transfigured shield (or transfigured charmed magical shield, in either case there's no reason someone couldn't have just magically LASIK-ed his vision), which would give him a defense against any non-Killing Curse spells that go his way from anyone he doesn't immediately kill. Then he lunges for (or accios) the pouch and cloak, retrieving Hufflepuff (Susan) Bones and Cedric, to help him fight the remaining Death Eaters (or go for help). Then he casts a Patronus to get McGonagall (and insists she not disrupt the game).

Ah, better yet - the glasses should be his broomstick. Or his broomstick AND a shield. AND a gas mask. Fit together (since glasses are composite objects anyway).

OK, so here's the attack plan, to tear apart Voldemort's plan at every possible point of intervention:

1) While transfiguring a long buckytube monofilament out of his own flesh, tell Voldemort about partial transfiguration, demand that Harry himself be saved in return.

2) Wordlessly cast the Patronus at Voldemort to try to throw him off balance - as a bonus, if he manages a worldess wandless corporeal Patronus it can do step 5 early, OR possibly block a Killing Curse (not sure).

3) Whip the buckytube around to slice through a bunch of Death Eaters. Simultaneously, wordlessly wandlessly finite incantatem the glasses to detransfigure his broomstick.

4) Fly to (or accio while dodging curses) the pouch, extract Susan and Cedric, put on the cloak. They know from battle class that they should lift the sleep spell on their ally Hermione. (Harry shouldn't since it would be an interaction with Voldemort's magic that would be more likely to harm Harry than Voldemort.)

5) Cast a Patronus to get help from McGonagall (who can use her time turner so as not to disrupt the game), telling her to bring every competent battle mage she can get.

6) Cast Stuporfy at Voldemort to try and trigger the magical resonance, then fly straight at him to give him a hug.

Question for EY:

In the chapter, you wrote:

If a viable solution is posted before 12:01AM Pacific Time (8:01AM UTC) on Tuesday, March 2nd, 2015, the story will continue.

Does this mean that the reader-suggested solution will in fact be used, or will the story simply continue with the solution you originally had in mind?

Posted on ff.net: Harry realizes that his true power the Dark Lord knows not is his ambition to master the fundamentals of magic, in contrast with how proud of himself Voldemort was for developing one original ritual. Harry cannot explain this to Voldemort-that would go against his Vow. However, he can drop some very juicy teasers in Parseltongue; in particular, he can imply that his secret holds the cure to Voldemort's ennui. It might go something like (in Parseltongue):

"Though you are ambitiouss, you have no ambition. That iss true power Dark Lord knowss not-my ambition. I could purssue ssafely, but cannot trusst you will, sso cannot tell. Do not think can devisse ssafe hint in time I am given. Keep me alive, and perhapss ssomeday I can sshare-maybe I create ssafe hint, maybe I ssee change in you, or come to believe it besst that you know. Or kill me, and learn how long killing idiotss sstayss interessting. Conditionss for creating another like me may not be as ssimple as you think"

I'm so confused about the wand. Why does Harry still have the wand? Obviously Voldemort should have demanded that Harry drop the wand before giving him 60 seconds to speak.

"You needed worthy opponentss,"

Harry can do a lot of things, but V already knows many of them. His strongest options are things he's sure V has no idea he can do, like the swerving hex he used on Moody.

EDIT: His strongest options for ways to outwit LV, not things to tell LV to save friends.

Working backwards is a standard strategy for solving puzzles like this. Let's imagine Harry having gotten out of the predicament. How does the situation look? Where is Harry? Where is Voldemort? Where is Hermione?

Edit: TL;DR I made equivalent problem. It is sufficient and necessary. Prove: p(H causes destruction | H is Alive) < p(H causes destruction | H is Dead)

I have exams so I don't have enough time to do the whole process, as it should be done. I wanted to donate my thoughts and hope for someone else to do the job.

If you remember, we are not supposed to give solutions at once, we should talk about problem first. This includes gathering fair knowledge about all the mechanisms mentioned.

I see some people listed available objects, which could be used in open combat. Which is exactly what we should do, given that the problem is how to fight them. The problem is, however, not how to win the fight.

Now, I have to admit i haven't thought about the whole problem (I am not facing 37 Deathe-Eaters, true, but I am facing 3 exams next week), I focused on two things: Harry's mind, and Voldy's mind. I will deduce if Harry will actually try to defend himself.

These are my thoughts:

• Voldy (V) wants to stop the prophesy. Prophesy says Harry will cause great destruction.
• Harry (H) cannot change V's utility function.
• V's utility function has high preference for this world not being destroyed.
• V tried to maximize this function. (He showed he is quite "rational" up until now)

This is part where I imagined myself being V.

"H will cause great destruction. There is greater probability of him causing destruction, than his death causing destruction. Therefore i have to kill him. I just resurrected Hermione, so, someone can resurrect H. I have to stop that, so i will destroy his remnants."

• H did the whole Unbreakable Vow thing => he is now practically the only human who has no options when it comes to destroying the world.

• H's utility function is practically the same as V's utility function now. (Both V and H prefer world over H)

• "There is a prophesy i will destroy the world. I don't want to cause destruction. Is probability ("i cause destruction" if "I am alive") greater than ("I cause destruction" if "I am dead")? Whatever probability is lower, i will do that. "* (He can't chose anymore, he sacrificed it

  H would not try to live if that would lead to greater probability of mass destruction. He would prefer himself dead over alive. (If he is rational he would do that, because his utility function is such.)

Now, let's see compare pA = p(H causes destruction | H is Alive) and pD = pp(H causes destruction | H is Dead)

Vow ensures that if there is even a minor risk of H's next step creating destruction, he would have to interrogate that risk, and avoid it if there really is such a possibility. With regard to this and H's cleverness, he could cause something destructive much easier while absent than while present. =>
pD>pA

Since I don't see EY killing Harry or being inconsistent, pD is probably indeed greater, whether or not my deduction has flaws.

On this deduction depends whether or not H will actually do something to defend himself. If he will defend himself, he might as well communicate all this to V and he will let him go, because V prefers no destruction over destruction.

Edit: formatting.