Tick. Whistle. Hiss. Hum. Pop.

Harry sat in Professor Dumbledore's office, feeling more... blank than anything.

Now what?

He felt as though he'd run out of road, like the world had come to a sudden jolting stop and he hadn't. Quest complete.

Harry closed his eyes and breathed deeply.

What do I need to do now?

It felt strange, sitting here while the world bustled happily on. Voldemort was gone, unmade forever. Severus Snape had fallen in battle - Harry felt a rush of sadness at that - but he knew that that was an amazingly low price to pay, to prevent another Wizarding War.

Forget the future, what are my immediate priorities?

Harry was still trying to sort through his final inheritance from Voldemort. He needed to research how magical power worked at some point. So far, he felt bigger in some undefinable way. He was fairly sure that that was the feeling of the large "pool" of magical power he'd inherited from Voldemort, but cursory experiments (he'd tried snapping his fingers to conjure a banana again) hadn't worked.

Hermione had been taken to St. Mungo's. They would find nothing wrong with her - only Fiendfyre could hurt her now, with her unicorn blood and troll healing and a Patronus burning bright inside her.

Perenelle Flamel was in his pouch, cold and Transfigured into a diamond. For all that she had more blood on her hands than Voldemort ever had, Harry couldn't in good conscience let her die. It would also be useful to see if she knew anything interesting.

Of course, that would require the Philosopher's Stone, which left another problem.

Professor Quirrell, Harry reminded himself again, was not a good person.

Harry had been incredibly irrational when it came to Professor Quirrell. Looking back, he could apply terms like "motivated cognition" and "Halo Effect", to explain - or excuse, if he was going to be harsh - why he hadn't noticed that the Defence Professor of Hogwarts was a sickly, slowly-dying victim possessed by the spirit of a far more powerful Dark wizard, but at the time...

Harry was going to have to be a lot more cautious and a lot more introspective if he wanted to survive, let alone succeed.

He was going to have to look at everyone and see them clearly - without his own prejudices getting in the way, without Tom Riddle's fatal habit of seeing other people as, well, NPCs.

And he also couldn't afford to idolise people, especially not homicidal Dark wizards.

Nihil supernum.

And so Harry sat and considered David Monroe, as he knew him.

Quirrell was sensible... if he valued human life at all, it was not absolutely unreasonably optimistic to suggest that he could be persuaded to surrender the Stone, so long as Harry swore to give him access to it. If not... Quirrell wasn't invulnerable.

As for what Quirrell wanted...

Quirrell wanted to live, above all. On one level, that desire was effectively granted by virtue of the Horcruxes, and Harry had no power to threaten it.

That said, Quirrell had been worried that Harry might destroy the world, and all his Horcruxes with it.

Harry took little comfort from the Horcruxes. Even if the measures against things like torture and Obliviation Quirrell had spoken of applied to Harry as well, Harry was sure he could find some way. Harry needed to start taking precautions against ritual sacrifice...

Albus Dumbledore appeared in a flash of fire.

You will be polite, said Hufflepuff. You will now be sensible. You will not lash out at the most powerful wizard alive just because Tom Riddle didn't like him.

Harry looked carefully at the Headmaster.

Albus Dumbledore had fought a war against an enemy who simply outmatched him, and it had almost broken him. He'd carried on nonetheless, because there was nobody else. He knew better than anyone the hero's burden.

Harry had been a fool not to re-evaluate the Chief Warlock, when it became clear that he was sane. He'd been a fool not to tell him what he knew. Dumbledore was wise, and he was good.

Nihil supernum.

And yet, for all that, Dumbledore still thought that death was the next great adventure. He still had decided not to investigate the Philosopher's Stone, probably because that had seemed like something Voldemort might do-

Harry winced as Dumbledore punched cleanly through his Occlumency barriers, flicking quickly through his memories.

The Headmaster raised his hands apologetically. "I am sorry, Harry, but I had to be sure Lord Voldemort had not taken control over you."

And make sure you got all the Flamels' lore from me, Harry thought but did not speak aloud.

Headmaster Dumbledore sat down heavily. He reached over and scratched the top of Fawkes' head.

"Congratulations are in order, naturally. Well done, Harry."

Harry shook his head slightly. "I shouldn't have had to do that to anyone. And Professor Snape... I made a promise, when..."

Dumbledore looked gentle, but measuring. "Tell me, Harry. What was going through your mind, when you faced Voldemort? When you saw that he was winning?"

Harry looked down at the desk. Your anger with Dumbledore is the anger of a dead man. Your reasoning is artificially impaired.

"I needed some way to kill him permanently. It wasn't until after I thought of the ritual that I realised it would kill Hermione as well."

Dumbledore sighed, and all at once he looked like an old man again.

"I do not wish to mar your triumph, Harry, but-"

"I'm not stupid, Headmaster. I-" Harry cut himself off and took a deep breath. "Let me start again."

Harry closed his eyes, composed his thoughts.

"I am sorry, Professor Dumbledore. Some things I've said to you in the past were... unfair. Vindictive. Frankly, cruel. Voldemort hated you, and so..." Harry trailed off. "I did listen to what you said after the trial. I knew about it even before then. I was going to sacrifice Hermione to kill Voldemort, Legilimise me if you don't believe me. I just... thought of something better."

Dumbledore's gaze remained stern. "You did not know. Even with the Time-Turner, you did not know. Your future self might have lied to save Hermione. You still do not comprehend the magnitude of suffering-"

Professor Dumbledore had stood, and turned towards the direction of his Phoenix Price room.

"There was a Plan B."

Dumbledore halted.

"Voldemort's magic couldn't touch mine. The effect was worse for him - it killed him once." Harry smiled grimly. "My Patronus thought is something I can desire to share with anyone, even Voldemort. Plan B was to summon my Patronus and tell it to follow Voldemort. He'd never be able to return properly again, and we'd be able to track him down and sacrifice him if he ever tried."

Professor Dumbledore was staring at him.

"You... weaponised the Patronus Charm."

"I'm not a psychopath, I'm just very creative."

Dumbledore sat down in his chair even more heavily.

"Ah," said Harry, "that reminds me, actually. Now is probably the time to tell you what the Philosopher's Stone actually does."

Professor Dumbledore nodded. "Master Flamel only ever hinted. I thought it unwise to pry..."

Harry suppressed another flash of irritation. Prying into secret magic gets you killed. Dumbledore had no reason to think "Flamel" was lying.

"The Elixir of Life is a myth. The Stone makes magic permanent. And it can heal people, heal damage modern magic can't, things like... well, like Cruciatus damage."

Dumbledore flinched. "He lied, for all those years... kept it away from the world..."

"I don't suppose," Harry said, not wanting the Headmaster to lapse into more regret, "you have any idea why one object would make magic permanent and cure brain damage?"

Harry wasn't even sure that that reasoning was valid at all. He lived, after all, in a world of magic. For the first time, the terrifying thought was starting to occur to him that maybe the world just didn't ultimately make sense.

"As I said, I know very little of the Stone, Harry. I have, however, just now been trying to rectify that gap in my knowledge." That explained where Dumbledore had been.

"There are references, scattered ones, to the Stone of Alethiontology, the Stone of True Being. I had thought it mere legend, but it seems likely that the Stone in fact has only one effect: to render any substance, magic or indeed person the true thing. How that is determined, I cannot say; still less, how it is brought about. All I will say is that it is at least the second most powerful artefact I have ever heard of."

"Yes. And now Professor Quirrell has it."

"I suppose it would be optimism to the point of foolishness to expect that he would hand it over."

Harry shrugged. "It won't be easy, but if it comes down to it, we might be able to seize it from him. And... maybe, if he could be persuaded that it made me less likely to destroy the world..."

Dumbledore looked at Harry oddly, then.

The old wizard leant back in his chair and rubbed his eyes.

"Harry, it seems you already know something of your... situation. There is something I must show you."

OoOoO

Harry beheld a long stone hall, stacked with shelves, feeling faintly unsettled.

Upon the shelves rested small white orbs, shining eerily in Dumbledore's wandlight. Some of the orbs were polished and gleaming, but others lay beneath the dust of centuries. Somehow, though, they all seemed to belong equally, and there was no trace of any human hand disturbing those shelves to place the orbs.

There was a blurring effect around the orbs and a sort of pressure in his ears that Harry didn't think was part of the magic of the place.

The place was of a magnitude Harry would never have expected. The rows of shelves stretched into the distance - Harry guessed there were at least a hundred.

That seemed unusual, really. How many wizards in Britain - no, let's assume it's the whole world, so a million. We don't know how rare Seers are, but people seem to accept it as plausible that there'd be one or maybe even two in Hogwarts, so say one in a thousand. Seers never make many prophecies in a lifetime...

This place must have been ancient.

"This," intoned Dumbledore, "is the Hall of Prophecy, Merlin's gift."

Dumbledore withdrew from his robes the device of the Chief Warlock, the Line of Merlin.

"When our war against the Dark Lord was failing, for all my magic, despite all the Order's efforts, I came to this place and did what no other had done in recorded history. I invoked an old password and listened to every prophecy recorded here. I learned that Voldemort was the least of my worries."

Dumbledore gestured expansively. "This Hall is perhaps Merlin's greatest feat. There are hundreds of thousands of prophecies recorded here, from all over the world. Many of them are connected, and many of them are already averted. I have not listened to all of them, but all those I have heard point ultimately to one thing."

Dumbledore placed a withered hand on Harry's shoulder. Harry realised he was holding his breath, and released it.

"This world is ending, Harry. Again and again, prophecies foretold the end of all life. Whenever I heard one such prophecy, I terminated its line of possibility. Whole shelves of prophecies I averted, whole lines of foretold tragedy I circumscribed, with a well-placed word or spell."

Professor Dumbledore's gaze was fixed on Harry. "And then came your prophecy, Harry. By rights, I should have ended your possibility, prevented you from ever being born. You will end this world, Harry. That much is inevitable. Whether that means merely life as we know it, or this planet, or all existence, I do not know."

Quirrell was right. "Then... what..." Harry trailed off. If he was going to end the world - why hadn't Dumbledore killed him-

Dumbledore smiled, and there was a gleam of something like triumph in those sapphire eyes. "In your case, your case alone, there is the slightest of loopholes. You, Harry, shall end the world, not life. I do not know how you could do it, but you have ever been blessed with more imagination than I. You may yet rescue this world's peoples, though their home may be doomed."

Well.

I suppose it could be worse. We still have Dumbledore and Professor Quirrell and Hermione...

Harry suppressed a shudder. Something didn't feel right about this whole situation - which he supposed was fitting.

Dumbledore shook his head, as though to clear it. "And that is what I have dedicated my life to. That has been the ulterior motive behind... oh, at least nine parts in ten of my apparent madness. At the bidding of prophecy, I crept into your bedroom while you slept and administered the Sleep-Cycle Potion. I gave your mother Lily the means to help your mother Petunia, ensuring you would grow up surrounded by science. I used the Ventriloquism Charm to tell you to look for Hermione. When you were very young I cast a Reductor Curse at the rock on your windowsill, and to this day I still do not understand why."

"You killed my pet rock!"

Harry had found his voice at last, and that was what he'd blurted out.

Dumbledore chuckled.

Harry cleared his throat, ears burning slightly. "Can I hear these prophecies?"

"No. They are very clear that you must never hear them. I have heard all the recent prophecies that have not been already averted, Harry. They are of no further use, that much is clear. To that end..."

Dumbledore raised his wand and cast a spell Harry now recognised as Enai's Greater Destruction.

Thousands upon thousands of glass orbs shattered, the legacy of Merlin lying in fragments upon the floor.

A mass of ghostly Seers arose, and for a brief moment the innumerable voices sounded like the roar of a jet engine even through the Charm on Harry's ears.

Then Dumbledore flicked his wand, and the images and glass fragments vanished.

The Chief Warlock raised the Line of Merlin Unbroken and touched it to the wall. There was no visible ceremony, no bangs or flashes or puffs of smoke, just a quiet sort of dying feeling as though someone had suddenly unplugged a television that had been on, unnoticed, in the background.

"And so we face the future unknowing, as it was before Merlin."

The two wizards burned out of existence, leaving only the silent shell of the Hall of Prophecy.

OoOoO

Professor Quirrell appeared in the dark street without a sound, and drifted into a slightly run-down cottage.

Inside lived amongst the most esteemed of magical historians, but she was old, withdrawn. She was into her third century, ancient even for a witch, and slowly dying. The Healers' arts were failing them more and more as Merlin's folly eroded wizardkind, and nobody still living could coax such damage to heal. Still, her magic was with her, and she refused all offers of help.

The Death Eaters were long since disbanded, and they had never been suited for such work as this. David was no fool. Riddle's little habit of underestimating other people had killed him, and it was time and past time for David to learn from his mistakes.

If he was going to save the world, it might be nice to have help. Prophecy was far from understood, but the best place to start might be here.

Nobody would be suspicious about the "death", not with a perfectly realistic corpse courtesy of the Stone.

"Somnium, Legilimens," Quirrell said to the sleeping form, extracting all the fragments of old lore, all the knowledge of influential people that the great historian had ever accumulated.

It was the work of a second, to sweep his wand over the sleeping woman and fix the Transfiguration with the Stone.

"Innervate".

The woman sat up in bed, gasping, and it took her a moment to realise that she wasn't in any pain.

"Good evening, Ms. Bagshot," came a cool, precise voice. "I have a proposition for you."

OoOoO

There was quiet, for a time, back in Dumbledore's office, save for the constant noise of the artefacts in the background.

"I'm sorry," Harry eventually said again. "All this time, Professor, you were the sane one... the only one doing the right things for the right reasons..."

Dumbledore shrugged lightly. "I long since ceased to care what others thought of me. Life has far fewer headaches that way."

He grew serious again - sombre, even. "Harry, in truth, I did not expect to survive Voldemort's downfall. I did not expect you to deliver us another miracle, to end Voldemort so soon. I am gambling literally everything on you, now. This is, as I'm sure you need no convincing, of quite literally the utmost importance."

Dumbledore reached into his robes for the Line, and passed it unceremoniously to Harry, without hesitation.

"Merlin's legacy is yours. Do not uphold it. Surpass it. That is your burden, Harry. I give you everything I have - the Line, leadership of the Order, all such resources as I can command. I will gladly share any fragment of lore you require. If you can find some way to overpower me somehow - preferably without killing me, if you wouldn't mind - to take the Elder Wand, do so. Your survival is imperative."

Harry took the Line.

Nothing visible happened. Merlin had not shared the Peverell's more ostentatious excesses.

The Line did not grant its wielder any secret magical powers. It simply granted them control over the Wizengamot, and let them monitor the Department of Mysteries, and opened certain very interesting vaults...

It didn't allow the Chief Warlock to break the Interdict, not even with the world at stake. Merlin had planned millennia in advance, and the Line could not tell what its wielder would be inclined to do.

"Merlin, you idiot..." Harry muttered.

"Come again?" asked Dumbledore, one eyebrow raised.

"The Interdict. It stopped people from ending the world with dangerous magic, but it didn't have any measures built in in case people needed powerful magic to prevent some other threat."

"What would you have done instead?"

"Used the Mirror," Harry replied promptly. "It shows your coherent extrapolated volition. If I'd made it, the Interdict would censor powerful magic unless you stood in front of the Mirror and it showed you not ending the world."

"Alas," said Dumbledore. "Even Merlin did not consider everything." He steepled his fingers. "I cannot, at present, conceive of any means of lifting the Interdict, but that does not mean it is impossible."

Harry yawned, the events of the day finally catching up with him.

"I doubt you will have time to lead the Wizengamot, and frankly it is a bureaucratic nightmare I would not wish upon Voldemort himself. I suggest you appoint me as regent."

Harry nodded wordlessly, and returned the Line of Merlin..

Dumbledore seemed to understand. "My office is open to you, Harry. Come at any time. There is more I must discuss with you, but it can wait. Sleep well."

Harry stumbled from the office.

OoOoO

An infinitesimal fragment of ruby positively glittered with enchantment beneath the microscope. With the slightest spell, it adhered seamlessly to the Philosopher's Stone, and its magic became true.

OoOoO

David appeared before a quarantine room of St. Mungo's hospital. Hermione Granger slept within, next to a box of rats and flies.

Knockturn Alley was home to many who would not be missed. One such individual lay now in an enchanted sleep, floating eerily.

This was absolutely necessary, as even those called good would agree.

What could charitably be called a life ended in a flash of green.

The Dark wizard stood, murmuring the spell of the Greater Horcrux over Hermione Granger.

After a time, a small item disappeared into his robes, and Quirrell and his victim vanished as though they had never been.

There was a resigned sadness across the nation the next morning, when it was found that Bathilda Bagshot had died peacefully in bed.

Nobody noticed the disappearance of another nameless petty criminal.