"Heh?" Dumbledore echoed. From behind a pane so pristine and perfect it could have been a portal to another world – and hopefully would become a portal to another world at some point in the future – the headmaster adjusted his half-moon glasses and squinted. "Harry? Is that you?"
"Call me Silver," was his automatic reply. But a moment of thought later, he realized how pointless it would be to obscure the conversation, given how much there was to obscure. Even though he'd gotten into the mental habit of referring to himself as 'Silver' whenever he was in pony form, he could make an exception. "Actually, never mind. Harry's fine, headmaster. With all there is to talk about, I don't think aliases will matter all that much. If anypony overhears this, I'll be in trouble either way."
Dumbledore stared at what must have looked to him like a floating pony head. He looked sombre and terribly serious. His ancient sapphire eyes were not, at the moment, twinkling. "If you speak true, Harry, then I'm sorry for doing what I must do next, but if you can think of any way to prove yourself to me, I would greatly appreciate it, for I can think of none myself. None that Voldemort could not simply fake. Otherwise, I think it best if I assume this is a trick and ignore everything you say."
That put a damper on Harry's glib mood.
Right.
When the headmaster first appeared a few minutes ago, he'd been panting heavily, as if adrenaline had just gone through his system moments before he'd appeared. It looked like he was recovering from panic and shock. It could be something else, but if the mirror really did trap things in frozen instants whenever a third party is destined to retrieve/consult them in the future, then... then that means no time has passed for him since he shouted "No no NO!" a year ago.
From Dumbledore's perspective, in the span of the past five minutes, the headmaster had just...
1. Had an unpleasant conversation with Lord Voldemort in order to stall him long enough to vanquish him.
2. Watched as Lord Voldemort escaped the teeth of his trap at the last second, leaving his hostage – The Boy-Who-Lived – behind in his place.
3. Next the headmaster tried to reverse the mirror on just himself.
4. Then he'd seen that his trap had worked after all, with Voldemort locked outside of Time and inside the body of a pony.
5. And now, after telling Voldemort he will never be free, he's seeing a pony claiming to be Harry Potter.
That probably didn't look good.
Harry tilted his head in consideration. What couldn't Voldemort simply fake?
"I take it I can't just say that you gave me an ice cream soda after I made my first original discovery? A discovery that had to do with Transfigured parts? You know, to prove it's really me?"
Dumbledore paused, then slowly shook his head. "You are not a Perfect Occlumens, Harry. Even if you were, anybody can be turned traitor with enough torture, or a good enough lie. You have convinced me that you are probably not a false image. You have not convinced me that your intentions are still good."
Oh. That's all he had to do?
At once his Patronus appeared, carefully willed into the shape of a human rather than a pony, to avoid confusion. He felt his head and back and tail lighten as his mane became ethereal. "Tell the headmaster I've got a plan to vanquish Voldemort once and for all, just like I got rid of a certain Death Eater."
His Patronus didn't even have to walk to deliver the happy news. It simply turned and repeated the message.
Dumbledore, when he replied, sounded distinctly worried. "What Death Eater would that be, Harry?"
"I got rid of the heir of Malfoy, future Death Eater, and replaced him with Draco, friend of Hermione Granger and future asset to all of magical Britain."
There was a certain pause.
"I see," said Dumbledore, no longer sounding worried, eyes twinkling madly, fond smile firmly in place. "And you believe you can do the same to Voldemort?"
"Not exactly. I believe you can do the same to Voldemort."
Dumbledore stared at him, mouth open.
"Er, sort of," Harry added. "You and one other pony."
"Eh..." said Dumbledore. This was only the third time Harry had ever seen the wise old wizard at a complete loss for words. The inevitable request for clarification did eventually come, though. In a completely confused tone of voice, of course. "How?"
"By giving him what he wants," Harry replied with an evil grin. "He told me to convince you. I mean, he literally left me a note saying 'convince him' on the ground over there. So you're going to tell him that I've convinced you to undo the trap once he can perform the Patronus Charm version two-point-oh. Like I just did."
The headmaster's mouth stayed open. "That is not... he would not..."
"He'd never be able to learn?" Harry finished Dumbledore's unfinished thought. "I already taught him the gestures. Believe it or not, he's making a genuine effort to learn, even if his heart isn't in it. He does want the military advantages of the spell that sends instant, unforgeable messages, and I think this might be the push he needs to actually want to learn it. Oh, and once he does, make sure he has his Patronus send a message to you, so you know it actually is his Patronus. And if it can't take the form of a human, it's probably somepony else's that he's trying to pass off as his own. Be careful about that, too."
Dumbledore began stroking his long beard. "Harry," he said slowly. "Are you sure you are not being..."
"Brilliantly cunning?"
"Wildly overconfident and optimistic in his ability to change would say it better. There are some things that even the cleverest of plots cannot accomplish."
Harry's grin widened. "Normally, I'd think the same thing. But when you only give him the one option, and then give him an infinite amount of time to work on it, I'd say the odds are much better." Then Harry's grin vanished. "Also... um... it might help if you thought about what he said to you earlier. When he was stealing the stone, I mean. That thing about his last attempt at being a good person? I'm pretty sure he wasn't lying about that. I'm pretty sure that was the last straw for Tom Riddle. You were the only authority figure he ever trusted. So when he went to you for help and you gave him that lecture instead... it broke him."
In himself, Harry Potter had healed his broken dark side by reassuring Voldemort's neural patterns that it was right and proper to be horrified of death. His dark side could wear its fear as a badge of honor. That had been enough for the Boy Who Lived to seal the fault line within himself, to mend the part that had been broken. Unless Tom Riddle heard a similar reassurance from the headmaster, Harry suspected that Voldemort would never fix his OWN cracks. Assuming it wasn't already too little, too late.
Dumbledore paused in his beard-stroking. "I'm not sure I agree, Harry. I think he might have already been broken, long before I ever met him."
"He probably was," Harry agreed. "But you were the only person keeping him from going over the edge, probably the only person who could have fixed him. After that day, he didn't trust anyone. Not even Bellatrix Black."
The headmaster looked surprised at that.
"Oh, and that reminds me. You've probably guessed by now, but Professor Quirrell spun a sob story that convinced a young and naïve hero to break a damsel in distress out of prison, making her sound a lot like that hero's closest friend before Voldemort got to her. Afterwards, when that hero thought to question his true motives, Professor Quirrell claimed he did it so Voldemort's lore wouldn't be lost forever. And then when that hero learned the actual truth about Voldemort, he learned that the entire point was to find Voldemort's lost wand."
Dumbledore nodded, grimly and gravely. "I see."
"Out of curiosity," this was something he'd always wanted to ask, "when I was in your office later that day, why didn't you demand that I cast my Patronus, and then ask your own Patronus if mine was the same one from the breakout? You'd have unraveled the whole scheme if you did. Was there a prophecy telling you not to? Or did you already know it was me?"
A/N: Honestly, I think the real answer to this question is that Yudkowsky didn't think of it at the time, otherwise he'd have addressed it in-story. Maybe he already addressed it on the subreddit; I wouldn't know, I only discovered HPMoR after it was already written. He could have even given the tongue-in-cheek explanation that Dumbledore didn't think of it. That's what I'd do.
Either way, the following answer is my own best explanation, assuming it wasn't a simple mistake on his or Dumbledore's part.
Dumbledore shook his head. "No to both. I would have needed to maintain my Patronus all day in order to perform such a test. I dismissed it when I went to retrieve you from Mary's Place. While my Patronus was active, it could track the one that I asked it to track, even if the target was dismissed and recast. But at the moment of its own dispelling, my Patronus forgot the one I asked it to remember. Your Patronus, as it turns out."
"Ah."
So, even if Patronuses could act like bloodhounds and track other Patronuses, dismissal causes them to lose the scent. Harry wondered if his own Patronus would forget.
"You know," Harry admitted, "I was stressed out of my mind that I'd get caught because of that."
"Harry," said Dumbledore with tired eyes and a tired voice, his tone clearly indicating that he wanted to get back on topic. "Are you certain this course of action will work?"
"Yes."
"And you are certain it is what you want?"
"Yes."
Dumbledore didn't look reassured. "If I agree to the release condition you have proposed, it is very possible that you will be my age by the time he succeeds in casting the spell, if he casts it at all. Even if Tom does not take a century, you will certainly be too old to be recognized as yourself by anyone you knew."
"It's already been a year," Harry shrugged. He did not mention that he had no intention of staying even one day later than today. "Besides, I've got Hermione with me. Oh, and that also reminds me."
He removed the metal band from his back hoof and placed it on the floor.
Earlier, without asking for Silver or Memory's permission or forgiveness, Voldemort had stunned Memory and transfigured her into the metal band she'd been before her revival. He claimed he was 'recreating the conditionss of our entrapment ass clossely ass posssible'. He'd then told Silver that her form was locked in place so long as he was nearby.
It wasn't technically hurting Hermione, and she'd already been asleep at the time, but Harry had still felt very angry that his mentor was still resorting to things like this whenever it came to truly important matters. It made Harry feel less bad, less wrong about what he was about to do. He lit his horn and cast a finite to dispel the transfiguration, but then paused just before casting an innervate.
"Oh, and headmaster?" he said before waking her up. "His condition for helping to revive her was- hold on. Somnium." Just in case. "Riddle's condition was to make me promise that she would not be told he was Voldemort. She still thinks he's just Professor Quirrell. He didn't steal her remains, by the way. I did. And in case you're wondering, she's immune to transfiguration sickness now. I figured out how to use the Stone of Permanence, and he used it to imbue us all with the powers of mountain trolls."
Even Albus Dumbledore, defeater of Grindlewald, vanquisher of Voldemort, re-discoverer of the fabled twelve uses of dragon's blood, seemed to have a bit of trouble processing everything that the Boy-Who-Lived had just said.
"Stone of Permanence?" he finally asked.
"Makes temporary magics permanent," Harry explained, "like Transfigured gold, or a transfigured human being. Formerly owned by Pernelle, who stole it from Baba Yaga the Undying, the Dark Lady that could take any shape she pleased and heal any wound. Pernelle killed her, took the stone, and invented the persona of Nicolas Flamel to pretend like she'd earned the right to live forever."
Dumbledore swayed where he stood, but Harry gave him no time to reply.
"That story also gave other ambitious wizards a false path to pursue," the Ravenclaw/Slytherin explained to the intelligent Gryffindor, "and her public unbreakable Vows to 'protect immortality from the covetous' worked as a deterrent against other dark lords trying to steal the true stone like she did. A muggle psychiatrists might call that 'confession through projection'."
The headmaster said no words, but his emotions were plain on his face. There was agony, betrayal, and the distinct desire for it to not be true, but also a clear fear that it was true.
At the headmaster's expression, Harry's Hufflepuff sympathy kicked in. "I know it's hard to hear, but... well, take it from the boy who lived his first year of Hogwarts cozying up to his good friend, Lord Voldemort, without even realizing it. When you accept the truth about your mentor, you'll understand what Tom Riddle felt when you gave him that lecture. Sometimes, your mentors aren't all that you thought they were. Sometimes you lose them, and the manner in which you lose them might or might not ever allow you to get them back."
Now Dumbledore looked truly ancient. Tired, world-weary, and ready to rest for a long, long time. When the old wizard responded, it was with great sorrow and regret. "I... don't think Master Flamel is coming back, Harry, regardless of the truth. Voldemort killed him. Or did he prevent you from hearing that part of our conversation?"
"I heard, but I can revive the recently slain now," Harry said, and gestured his head at Memory Sunshine. "Like I did for Hermione. It wasn't a one-time thing, it's a sacrificial ritual. I'd lose some life and magic, but I can do it. Depending on when he arranged for her to die, it might not be too late. And Perenelle might be worth it, too, if for nothing else than her hoarded lore..." Harry trailed off, realizing he wasn't talking about the important issue. "The question is, headmaster, do you think I should bring her back, if what Voldemort deduced about her is true?"
Dumbledore waved a hand, conjuring a couch behind himself. Into this, he seemed to completely collapse, as if not only standing, but even sitting upright was too much for him now.
"I do not know," said the ancient wizard. "But I would at least like to ask Nicolas for the truth. Even if it is true, perhaps Perenelle had a good reason."
Hm... come to think of it, she actually might have. It was the cynical Professor Quirrell who had explained the truth of the stone's history, but even according to himself, he had to fill in the gaps with his own assumptions. Maybe Baba Yaga had done something to Perenelle, betrayed her somehow, or genuinely hurt her, and that was why the Goblet had rendered the Dark Lady defenseless. And afterwards, maybe Perenelle thought the stone has a limited number of uses, enough for herself but not others... and isn't that a worrying thought. Harry's really hoping Riddle figures out how to make more stones in this upcoming hiatus that he'll be involuntarily taking. You could say Harry's wishing it will happen.
Please work, please work, please work, he silently begged the mirror. Maybe this is what it feels like to pray.
Dumbledore didn't speak for a while. His head rested on one of the armrests of the sofa while his feet were kicked up over the opposite side. His eyes were closed. He almost looked like he was sleeping. Harry was considering the positives and negatives of waking him when Dumbledore finally addressed his master plan.
"If I do release the trap," he said at last, though he didn't move, or even open his eyes. "I will not be released along with the three of you when Time resumes. I do not know why the mirror has brought about this circumstance, but I do know what will happen when I bring it to an end. The mirror's process will simply continue as it would have. I will be trapped outside of time instead of Voldemort, as I willed in the final moments of its activation. That is why I am so hesitant to agree to your plan. Without me to stop him, and without you old enough to oppose him, the world's people would be lost."
"Well, yeah, if he's still evil when you let him out. That's sort-of the whole point of having him learn the Patronus charm first."
The headmaster opened his eyes and looked into Harry's, though he didn't move otherwise. "Even those who know the Patronus charm can do great evil, as Grindelwald did."
"Maybe when it comes to the normal Patronus charm. Mine works a bit differently. Also," Harry added, "believe it or not, the world's people might have already been lost if not for Voldemort. It wasn't just luck that stopped Nuclear Armageddon. A few well-placed compulsion charms across the muggle militaries of the world went a long way." Harry did get around to asking that question directly. "Er, you do know about nukes, right?"
Dumbledore shook his head, eyes closed again. "I do, but that is an easy enough lie for him to make. It is unverifiable. Unprovable. Easily claimed, easily faked, and not easily refuted, even under ordinary circumstances."
Silver hissed out a Parseltongue sentence to his Patronus, which then turned to Dumbledore and said "snakes can't lie" in normal speech.
Dumbledore shifted in the couch, sitting a bit more upright. "How ironic," he said. His eyes were no longer distant, and though they weren't twinkling, they shone with something like amusement and intrigue.
"You believe me just like that?"
"Patronuses cannot lie either," the headmaster replied.
A/N: So, important note here. This is not HPMoR canon or fanon. We never see a Patronus convey a caster's lie in HPMoR, but we also never see a caster try to convey one. We only see Harry mention, in internal narration, that his Patronus probably wouldn't be able to convey a message to Moody that contained the intention of torturing someone into insanity. The implication there is that Patronus charms can only spread 'good'/'happy' news, or information related to good/happy thoughts. For the sake of plot convenience, I'm saying that Patronuses can't convey the caster's deceptions either. Heck, I could take it a step further and say that the Patronus charm is where Salazar got the inspiration for that quirk of Parseltongue, at least in this universe.
Quirrell calling it "Dumbledore's trick of sending messages" implies that only Dumbledore and the Order of the Phoenix know how to send Patronus messages, at least in HPMoR canon, so I'm going to go out on a limb and say it's not a widely known or studied ability. Not enough to be used in courts like Veritaserum, anyway, even if 'no lies' was a feature of the charm. So, yeah. It's not HPMoR canon to say Patronuses can't lie, but it doesn't outright contradict any established rules or evidence either, and I needed some way to actually convince Dumbledore.
Oh, and I tried to make everything else in this chapter that has to do with the Patronus charm not only canon-compliant, but canon-plausible. If Harry's explaining something that's never explicitly hashed out in HPMoR, that's me giving my own best guess at how it works, like I did with the Azkaban thing earlier.
Proceed.
As often happens when provided with an absolute claim, Harry's brain immediately offered a counterexample. "I'm pretty sure Professor McGonagall's cat conveyed my lie during the Azkaban breakout."
"You can lie to someone else's Patronus," Dumbledore amended. "You cannot command your own to be dishonest. Not even with Occlumency. I suggest putting it to the test if you do not believe me."
"Okay." Even if he was on a time table, he could always find time for empirical tests.
Step one: perfectly pretend to be someone who actually believes that 2 + 2 = 5.
Step two: "Tell the headmaster that two plus two equals five."
For the first time since he'd first cast the spell, he noticed that his Patronus was wearing a negative facial expression. It was frowning in stern disapproval.
"I see," said Harry. "Tell him two plus two equals four."
It turned to the headmaster and said, "Two plus two equals four."
The headmaster nodded, acknowledging the message was received. "Ask Harry what he meant that you work differently."
"I cannot be cast by someone who does not hold sapient life as the greatest moral value above all else." His Patronus gave that reply immediately, with Harry's voice but without his instruction to speak. Then it continued speaking. "Killing is only acceptable when the target has killed others, therefore losing them the moral protection of innocence. Even then, killing can only be done to save more lives, and when there is no other choice. Hatred and malice are incompatible with my existence."
It was only as his Patronus spoke that Harry realized – clearly and consciously, not just as a vague understanding – that his Patronus, unlike the animal Patronus, has independent processing power. Just like that time in Azkaban when it raised its hand and told him that another Patronus sought it out. After allowing him some time to prevent Bellatrix from overhearing its message. That implies a certain level of intelligence and independence that this little spontaneous reply just brought to Harry's full awareness.
His Patronus was probably borrowing his brain's processing power, just like the Sorting Hat. Unlike the Sorting Hat, his Patronus's goals weren't different and alien. It seemed to be completely aligned with Harry. Or with his happy thought, anyway.
Hm... and if that is how it works, does that mean it's dangerous to maintain his charm for too long, just like it would be dangerous to wear the Sorting Hat for too long?
"Should you even be telling me this?" Dumbledore asked after silently considering the Patronus's message for a time. He had address the Patronus in turn, but it still brought Harry out of his own musings.
"Probably not," said Harry, drawing the old wizard's gaze back to him. "But honestly, I was thinking of telling you the underlying secret anyway. My Patronus picked up on that. Even if I was still set on secrecy, what it said is safe to say. I'm still not sure if I should tell you more, though."
"Do not answer if you must not answer," Dumbledore warned in a tone of firm command, "but can you yet say why I must not know the secrets of your spell?"
Now the headmaster decides not to pry? Dumbledore had been reprimanded by his own Defense Professor for his lack of wisdom when Harry first learned the spell. Had that been a test, or a genuine fluke? Would he have interrupted Harry if Harry had tried to say the secret of the spell?
Well, either way, at least he's being cautious now.
"You're right," Harry agreed. "I shouldn't answer that question. You aren't ready to hear the truth." It's not every day you get to say that to the world's wisest wizard. "And I wouldn't tell you under any other circumstance..." Harry sighed, his decision made. "But I guess this is an exception."
Dumbledore raised a forestalling hand. "Even in this anomaly of time and place, I am not sure you should tell me, given that I am not wise enough to see the answer for myself."
"I'll explain my reasoning afterward. Before I do, just know that it's all for the sake of Voldemort's potential redemption. Is that enough for now?"
The old wizard looked considering. "It may be," he allowed, "if all the other risks are mitigated, whatever they might have been. Are they?"
"Yes. They're mitigated. Mostly thanks to the mirror."
Dumbledore nodded. "Then I will trust your judgement, Harry. It is your secret, after all. Do what you think is most wise."
"Okay then." Harry drew himself up a bit more formally. He wished he was wearing his 'smart' outfit. "Are you ready to know the truth, Albus Percival Wulfric Brian Dumbledore, even though I think you're not truly ready to hear it?"
Harry's going to milk this moment for all it's worth, even if he does have to be all solemn and serious about it. Now HE can do the deep and mysterious revealing, thank you very much. And he isn't going to taint it with insanity either.
The headmaster, in response to Harry's important question, replied with equal importance in his own voice. "I am ready."
"Then first comes the reason why it must be kept secret." With the knowledge that he was about to get away with committing a cardinal sin of wizardry, he spoke, revealing the answer to a mage who was not wise enough to see the truth for himself. "Anybody who hears what I'm about to tell you will never be able to cast the animal Patronus again, and if they don't have the right mindset, they won't be able to cast the stronger version. They'd be left without any Patronus at all."
"Ah," said Dumbledore. "That is an excellent reason. I assume I am lacking that mindset?"
Harry nodded. "Learning the truth will break your Patronus like a soap bubble. And just like Lord Voldemort will probably need at least half a century to cast a Patronus charm with the upbringing he's had, it'll probably take you the same amount of time. For a completely different reason, granted, but a half-century all the same – actually, make that a full century. I made his prediction based on how long he's had to develop bad habits and thought patterns. Basically, I based it on his age. So if I'm being honest, my prediction is that you will need twice as long as him, since you're twice his age. Unless you make a dedicated effort to change your mind, that is. Before we go further, are you still willing to hear the truth, knowing you will never cast the animal Patronus, and maybe any Patronus at all, ever again?"
"Like Godric Gryffindor?" Dumbledore asked perspicaciously.
"Exactly like Godric Gryffindor."
"Then I am willing." But then Dumbledore raised a hand to prevent Harry from going further. "Though now that I know why I must not know your secret, if you can explain your reasoning for telling me anyway – why I may know regardless, even though I am not yet ready to hear it – please do so now. I will let you know if your decision is flawed by wise old wizard standards."
It was a good request, all things considered.
Harry took a moment to compose his thoughts. "As you can probably tell, letting the secret out would risk popping all Patronuses. I know I can trust you to keep quiet, but on general principles, the worst-case scenario is that some idiot, or some Dark Lord, overhears this conversation and tells the whole world."
"Can they?"
Harry shook his head. "I'm in the most secure vault in Equestria right now. In short, no. And even if we were overheard, Professor Quirrell already swore a binding Parseltongue promise to help me destroy all Dementors when we get back, and he's personally motivated to get rid of them all too, so it's not as bad as it seems. So long as there aren't any Dementors, it's not a disaster if there aren't many Patronuses."
"I... see," said the headmaster, stroking his beard again. "Even at the price of not casting Patronuses... yes. The destruction of all Dementors would be a net good, both for wizards and muggles alike. I think I agree. And you are right that Tom would be motivated to help you destroy them. That does indeed account for the secret's potential abuse, and it is unlikely regardless. Well then. Are there any other reasons for secrecy?"
"Losing any Patronus is sad, especially one as bright as yours."
The headmaster looked surprised at that. Or maybe flattered? "Oh?"
Harry nodded. "Right now, headmaster, yours is probably the brightest Patronus in the world besides mine and Hermione's. If I told you the truth, you'd lose that. I guess you could say that's one of the real reasons I don't want to tell you. And the thing about this situation that's making me consider telling you anyway is that you won't be there anyway. Even if you end the trap, the world won't have your Patronus. Not until we can find a way to free you too, which will probably take a while. And by the time we do get you out, there will hopefully be enough true Patronus casters to speed your own lessons along."
"I... thank you, Harry. But what is the benefit that would outweigh this admittedly diminished cost?"
"Your own peace of mind that the prophecy is at hand."
"Hm..." the headmaster drew out the syllable for a surprising amount of time. "You think that is sufficient justification?"
Harry nodded. "If it means you'll agree to what I proposed, then yes. The secrets behind the charm should allow you to see how this will 'destroy all but a remnant' of Voldemort, just like he already destroyed all but a remnant of Harry Potter when I was an infant. In short, headmaster, telling you the truth would help you understand why a Voldemort who can cast the true Patronus Charm wouldn't be Voldemort anymore. If Tom Riddle learns the spell, there would be nothing left of Voldemort but a remnant. Our two spirits would not be so different, and we would be able to reside in the same world together. In fact, we're already half-way there. My own spirit isn't that different from his now; ever since I learned how to cast the killing curse, our magics don't resonate so badly anymore."
"The killing curse?" asked the headmaster's disbelieving voice. "But your Patronus said-"
"Avada Kedavra."
The spell came from his horn, passed through the non-sapient air that Harry didn't care about, then struck his Patronus, which didn't even flinch.
The headmaster's eyes widened in alarm at the green bolt, then widened further as it was blocked.
"Harry," he said, "you are going to give this old heart an attack." The old wizard took a moment to just breathe. "How did you do that while maintaining your charm?"
"Voldemort's version of the Killing Curse doesn't use hatred, and he taught me how to use it. Or rather, he asked me the riddle that let me see the answer for myself, and then he taught me how to use it. It's the Killing Curse, version two-point-oh, which is basically the exact opposite of the Patronus Charm two-point-oh. I was surprised that they turned out to be useable at the same time, but now I don't have to worry about stray bolts going through walls and killing anyone."
Dumbledore looked conflicted on what his response should be, and Harry was proud to have made his day more surreal. "How could Voldemort have convinced you to learn such a spell?"
"How could Voldemort have convinced you to let him teach the killing curse to any Hogwarts student who wanted to learn?" Harry rejoined.
The headmaster paused. "Touché," he sighed. "The Defense Professor can be very persuasive. But I would still like to hear the answer. You know my own. You were there. The Defense Professor would be permitted to teach the Killing Curse if he succeeded in teaching a full corporeal Patronus Charm to a first year student, which I doubted he could do. That is how he convinced me. Now, how did Voldemort convince you, Harry James Potter-Evans-Verres?"
"Fair enough," Harry nodded. "It was a trade. Like the bet you made with him, except in reverse. He agreed to learn the Patronus Charm if I succeeded in learning the Killing Curse first. He said it in Parseltongue, so it was a binding promise. He also promised he won't stop trying until he succeeds, even if he's not all that motivated. What I'm trying to do now is give him the motivation. I thought it was a fair price to pay, especially if I didn't have to compromise my morals, which I didn't. No intelligent life was harmed in my learning of the Killing Curse."
The headmaster took some time to think about that, but he did eventually accept it. "If that is the only way for a Slytherin such as him to be convinced, then perhaps it was the right thing to do. Do you truly believe the prophecy could be at hand over such an exchange?"
"Yes." There wasn't an ounce of doubt in his voice. "Once you understand everything about the spell, I'm pretty sure you'll agree. Then you can agree to the release condition, and agree to keep an eye on him so he doesn't fake it and take the easy way out with clever tricks."
Dumbledore nodded further acceptance. "Are there any final reasons why I should not know the secret?"
"One last one," Harry allowed. "And it's the biggest one, actually. Since you aren't ready to hear the truth, the other major problem with telling you is that you might try to deny reality because you already believe something else. You believe the alternative so firmly that it's a core tenet of your whole world view. Hearing the truth will destroy that belief, or at least damage your ideology, whether you like it or not. And in order to eventually cast the spell yourself, your current belief system will have to be fully destroyed. Until then, you'll never cast a Patronus Charm again... and you might stop being my friend."
If not for the past year in Equestria, he might not have included that last part. But it was a true fear of his, and the headmaster would treat it with the same weight that Celestia would.
The headmaster let his words hang in the air for what felt like an eternity.
"I will not let this come between us," Dumbledore seemed to decide, "regardless of how the secret effects me." Slowly, the headmaster rose from the couch. "Your reasoning is reasonably wise by wise old wizard standards, Harry James Potter-Evans-Verres, and I find it acceptable." He rose to his full height and dismissed the cushioned loveseat, standing as stoically as if he'd never needed it. "I will hear the secret." The rod of steel that he'd lost when he'd seen Harry taken hostage by Voldemort was back in place, supporting his spine like the strongest titanium. "I am not Ravenclaw, but nor do I cower from truth."
"That makes you more Ravenclaw than most," Harry pointed out. "Sometimes, the greatest virtue a rationalist needs is the courage to face reality. Intelligence and clever plans and hard work can only get you so far. It wasn't the Ravenclaws of the world who hid Jews in their basements in Nazi Germany, or abolished slavery. It was the Gryffindors who saw the truths of those matters more clearly than anyone."
"Do not forget the Hufflepuffs who were too grounded by their friends to believe the lies in the first place," Dumbledore advised. "But thank you, Harry. I am glad you believe I am worthy of your house, if only in part."
"Are you really ready to hear the secret, then? Even if it breaks your Patronus?"
"I am."
"Do you want to try solving it yourself first?"
Dumbledore frowned slightly. "It is not a Gryffindor's way to rely only on one's self. That is the domain of Ravenclaw."
Harry thought back to his own lessons with Mr. Tome. Well... hints can often be as important to puzzle-solving and powerful wizardry as the solutions themselves. "What if I gave you a bit of help?" he offered.
"Ah," Dumbledore smiled. "Now that is a Gryffindor's way. As a mysterious old wizard, how could I refuse such a challenge from my mysterious young student?"
Harry's own lips quirked. "In that case, I'll walk you through how I figured it out."
"So be it."
"Okay. We'll start with the easiest problem then. Here's the question that made it obvious to me. If Dementors are a riddle, Headmaster, then what is the answer? What are they really? What do they symbolise? What lies at their core?"
Dumbledore's expression grew thoughtful. "I suppose fear is not the answer, then?" he asked after a pause.
"You tell me," Harry shrugged. "Every student who went to the Dementor saw something different. I didn't see anything at first, just a painful, open question. I could feel my mind trying to force a wrong answer into the question when I was looking at it, but my scientific training kicked in and prevented me from jumping to conclusions. That's why I went around asking everyone else what they saw. Remember?"
"I remember."
"Do you remember their answers?"
"Most saw dead, decaying corpses," Dumbledore answered. "That is true of adults as well."
Harry nodded. That wasn't surprising, given that Dementors symbolise death. "If that was all that anybody ever saw," Harry said, "the answer would be obvious. But you and I both know there are exceptions, since we are exceptions. Godric Gryffindor saw wounds in the world. You saw something that was almost exactly a human, except for the fact that it was a dark creature. Tom Riddle wouldn't say what he saw, so it was probably something so horrible that he wanted to pretend like it didn't exist. Everyone sees something different, which suggests that some people's minds are refusing to see the truth, or they're seeing different truths. With me so far?"
The headmaster nodded. "That sounds accurate. Though now I must ask a question of my own. In magical theory, Harry, and in the fields of literature and law, there are cases where no true answer can be found, only different interpretations. If separate truths are perceived, if the riddle of Dementors is subjective, how can you be sure that the meaning you have derived is most accurate?"
"Good question," Harry remarked. "The answer is that there are a few undeniable facts about Dementors that we can use, even when we can't trust our eyes. Dementors can't be destroyed, for example. They kiss people to death, they drain people of happiness, that kind of thing. So, keeping all that in mind, you tell me if this sounds right: What cannot be killed? Fear. What can kiss you and leave you in a permanent, unrecoverable state? Fear. What drains your happy thoughts, your life, and your magic when it gets close? Fear. Do you think that answer would get you through Ravenclaw's dormroom door?"
The headmaster did not answer right away. He took his time to actually think about it. And then he shook his head. "It would not."
"Fear is just the side effect," Harry explained. "Not the main problem. But people understand fear. They know what to do in the face of fear. They think of happy thoughts and loved ones to drive away the fear. Thus is the animal Patronus cast. A few rare wizards like you can overcome the fear completely. But even you still felt pain when you looked upon a Dementor. The Dementor still reached you through your Patronus charm. It still affected you because you have not overcome the final hurdle, and if you do, your moonlight phoenix will be gone forever. Are you ready to figure it out, or be told if you cannot?"
"Yes."
"Then answer the riddle," Harry urged. "What does drain happy thoughts and life and magic like an open wound in the world? What can steal everything that you are and everything that you ever would have been by a single kiss?"
Dumbledore didn't see the answer, even after his eyebrows had been furrowed for minutes.
Time to step it up. "I should also note that Dementors are called 'life-eaters' in Parseltongue."
Dumbledore still didn't see it.
Harry decided to just get it over with, finally asking the question that would seal the deal. "What stole your happiness more than anything else? What were you trying to tell me when you showed me the phoenix's fate?"
Harry saw it in the headmaster's eyes. Harry saw the exact moment that Albus Percival Wulfric Brian Dumbledore saw the truth.
Harry took a deep breath, then said it out loud anyway, just to be sure. "Dementors are death," he spoke the fateful words. "And the animal Patronus charm works by thinking of happy thoughts other than death."
Even as Dumbledore seemed to be convinced about the nature of Dementors, he also seemed to disagree with the statement about Patronuses. "My own happy thought involves death, Harry."
"It does." Harry already guessed that much. "And so does mine. That's why our charms are so bright. Your own animal Patronus charm is brighter than all the others because your happy thought involves your unwavering belief in the afterlife. Is my prediction wrong?"
The headmaster sighed. "It is not wrong."
"Thought so. You found a way to be happy about death, to think about life in the face of death. You think about how you'll see your family when you finally die. You see death as continued life, which is why you didn't see a dead or decaying man beneath the cloak like everyone else did. You just saw a tall, thin, naked man. He wasn't decaying because you believe people live on after they die. You believe they do not truly whither into rot and nothingness. You feel pain at their parting, but you believe they are not truly gone. The Dementor was only slightly painful to look upon for that reason. Does that analysis sound inaccurate?"
The headmaster shook his head. "I must admit that it sounds exactly correct, though I wish it did not."
Harry nodded. "Right. In that case, this next part will be the hardest for you. In order to cast the true Patronus charm, you must accept that there is no afterlife, headmaster. None that wizards can truly reach. And I can disprove it too... although some minds will always fall back on the excuse that it can never be disproven, which is what makes the belief so difficult to deal with. Still, are you willing to hear out my evidence, like I heard out yours? Fair warning: this right here is why you aren't ready."
The Headmaster didn't reply, instead drawing a wand from his robes – not the Elder wand which is in the possession of Tom Riddle. It looked more like something Olive-something would have made. Dumbledore's wand rose to the starting position of the Patronus charm. On the wand, his fingers moved exactly the right distances as it twitched once, twice, thrice, and four times. He raised it in a broad brandish as he shouted, "Expecto Patronum!"
Nothing happened.
Harry looked down at the ground. He knew it would happen, but he still felt guilty.
"I will hear your evidence, young Ravenclaw," said the headmaster's voice, "if you do not blame me for foolishly clinging to my own beliefs, as I do not blame you for breaking my Patronus. I am too old and set in my ways to be changed by anything other than dire need."
"I'll try not to get angry this time," Harry nodded. "So, here's the evidence. Voldemort tested the resurrection stone. He couldn't contact Merlin, or anyone else he didn't already know. He explained to me how to build a false veil, indistinguishable from the one in the Department of Ministries. And when he originally cast the horcrux spell, he did it by understanding the truth about ghosts. It wasn't a ritual at all. It doesn't tear the soul, and anyone who believes in souls can't cast it. The original Horcrux spell is like painting a portrait, except that it uses the burst of a wizard's magic after their violent death in the place of paint and parchment."
That had been Riddle's phrasing, in one of his private lessons.
"By channeling the death-burst through himself," Harry explained, "Voldemort created his own ghost and imprinted it on an object that could possess someone. But he lived on after the ghost was made. The ghost was not truly alive. It wasn't his true soul, or even a fragment. The ghost can't pass down interdicted secrets because the horcrux isn't actually alive. It doesn't update itself to the caster's current state of mind when they die for real. A horcrux is simply a self-portrait made at a single instance in time. Naturally, he realised it wasn't what he wanted once he saw the truth. And until you accept that truth, Albus Dumbledore, which I still think you aren't ready to hear, you will not cast the Patronus Charm again. It will not be an absence of light that halts your magic. What stands in your way now is your belief in life after death."
When his speech was finished, Harry noted that the couch hadn't been conjured again. He didn't know if he should be impressed or worried.
"I understand," said the wise old wizard. That said nothing about agreement, which Harry well knew by this point. But it was probably the best that Harry could have hoped for. Therefore...
"So it is done," Harry said, remembering the words the headmaster had spoken after Harry had made the phoenix's choice.
"So it is done," agreed Dumbledore.
"Of course," Harry continued, "Dementors and death are only half the lesson. Do you need a moment before we continue?"
Dumbledore shook his head in refusal. "Best to keep on while we are... on a roll, as they say."
That worked for Harry. "In that case, I'll just jump right into it. No riddles this time. When facing the true nature of Dementors, the happy thought you have to use is life. Whenever I cast the true Patronus Charm, I want death to be destroyed. I believe that death can be overcome. Not in the form of an afterlife. Not in the form of a life well-lived. In the form of everlasting life. The Stone of Permanence is real. I intend to make more if I can. Voldemort's immortality ritual is real, even if it needs adjustment. I don't want to say goodbye if I can do something about it. I don't want to pay the phoenix's price if I don't have to. At the cost of life and magic, my Patronus can revive the recently-perished. At the cost of caution and advancement, science and magic can prevent death from happening in the first place."
Harry was getting more and more excited as he spoke. His Patronus was getting brighter. His mane was probably getting brighter. He couldn't help it. But then again, maybe he shouldn't help it. The brightness might help.
"Death can be defeated, Headmaster! Humans don't have to die. Voldemort understands that much, so in a sense, he's halfway there. He's completed the part of the path that ends in the understanding that death is horrible and doesn't have to happen. He completed the journey that you still need to take. And you've completed the journey he hasn't taken, the one where you know that life is only made meaningful by the people and ponies you meet along the way. You have to do both to cast the true Patronus charm. Godric Gryffindor either kept his true Patronus a secret, or he didn't quite finish the journey. He didn't reach the point of believing that death can be broken, even though he saw its shape as a great many wounds in the world. You, Albus Dumbledore, now stand where he stood. Even if you never cast it yourself, do you understand why it must be kept secret?"
"I do."
"Do you understand what it means to cast the spell?"
"I wish I did not."
"Do you understand what it would mean if Tom Riddle manages to cast it?"
"Yes."
"Then I think that's all there is to be said. Tempus." And just in time, too. He only has five minutes left before the ward circumvention ends. "Want to say hi to Hermione before we go?"
Dumbledore paused, then shook his head. "She would question why I am inside this mirror, and I would be tempted to answer. Go, Harry. I will tell Tom how he might be released, tell him the test he must pass, and I will make sure he does not cheat when he takes it."