REPAIRING IGNORANCE

The door swung shut behind him with a gentle click.

He had said he would only need two minutes. He hadn't lied.

It would either work or it wouldn't. Everything he had experienced so far seemed to suggest it would, and the hope burned in him like a raging inferno.

If it didn't work ...

The time-turner could accomplish nothing. He had no resources, no leads, no way to choose between a thousand threads of potential research. No one with the knowledge required to guide him could be trusted, not with this. None had the right motivation; the appropriate motivation for this time and this place. They would keep him occupied and distracted.

And those that would help, those who were coming to understand the world as it was, they didn't have the knowledge.

It burned deep within him, that understanding. With a few well-chosen questions to someone with enough power and he could have narrowed his search immensely, perhaps constrained it enough to fit within the time-turner's limit. But there was no-one to ask. Even the defense professor had been evasive, tempting him to waste his time. Any answers he provided would be suspect.

So all he had left was his own hubris.

He could practically hear her voice, words of warning he had never heeded. Unintended consequences. The risk of vaporised death that lurked hidden inside transfiguration experiments, the improved Patronus that swallowed life as fuel.

Not for the first time he cursed Merlin and his Interdict. The recursive irony of it; to hide the knowledge of dangerous spells one also obscured the risks associated with their rediscovery. Any witch or wizard could not know if a simple tweak to a minor spell, something a first year could do by accident or design, might unravel the foundations of reality. Magic didn't work on proportionate reactions, and taking away the knowledge took away the ability to avoid calamity.

If he had known that to destroy a single dementor would simply tire him out, but to defeat a group would take more than he could give, he would not hesitate. He would draw up a roster and work in shifts, until every scar in the world was closed.

But not knowing almost killed him, when the light filled him and his life poured out.

He shook his head. It was one thing to know about the over-confidence bias, to have trained to account for emotions like hope when making his decisions, it was completely another thing to have no remaining options. To be lost and drowning and to know that you had one last chance to breathe clean air.

He had read Kahneman and Tversky of course, the fathers of modern rationality. But beyond their work with heuristics and biases, he had also learned about framing. The earliest experiments showed that the way a question was asked would change the answer. The external environment influenced the decision as surely as any emotion could. He got that, on a cognitive level.

Until now he never understood the implications beyond the elegant research papers. Questions are not only asked by people, but by situations, and faced with an unknowable risk, or a knowable and devastating loss, he had to make a decision.

Harry Potter smiled sadly as he looked upon the body of Hermione Granger.

For whatever happened next, he blamed Merlin.

He lifted his arm, his holly and pheonix feather wand trailing streamers of golden light as it angled towards the still form that had been his friend. He uttered a single word.

"REPARO."

Muscles, bones, joints.

Springs, levers, pulleys.

Vessels, airways, gut.

Pipes with flexible or muscular walls.

Heart.

Pump.

Liver, spleen, kidneys.

Filters.

Nerves. Neurons.

Wires. Logic gates.

Cells.

Microscopic machines.

It wasn't enough, he knew. He pushed further.

Life.

Self-replicating and self-organising automata. Complexity from simplicity.

Id. Individuality.

Noise. Muddy signals. Probabilistic fluctuations.

Ego, self.

Recursion. Self-referential fitness mechanisms.

Super-ego. Rationality.

He paused, slowed by the cognitive dissonance of the thought, but pushed onwards.

Weighted reflexes. Aggregate external phenomena. Even more deterministic than the rest.

The wand grew brighter, ribbons of light coiled around the length, twisting impossibly through invisible dimensions.

There was still something missing. His eyes searched her motionless face, scoured her features, but could not find the key. The power in his wandtip pulsed and threatened to escape. Confusion was detected, and a well-trained pathway turned the anaysis inward.

A specific group of neurons fired and caused his lips to twitch upwards.

What do you think you know, and why do you think you know it?

The Hermione he imagined.

Mental model of reality. Flawed. The map is not the territory.

This wasn't transfiguration, partial or otherwise. He wasn't changing a thing that was into something he imagined. He was simply returning something broken to an earlier state. He looked at her and saw her. A pattern, no more and no less than any other.

The light expanded, spreading across the floor like liquid.

The disciplinarian blinked as a glittering corona of light flowed out from behind the closed door. The walls and floor turned to shimmering gold, under her feet and behind her back.

She closed her eyes and prayed her trust had been well placed.

An old man stood in a hidden room before hundreds of broken wands, lost in thoughts long trodden.

Downstairs a phoenix cocked its head in interest as several instruments that spun and twirled began to glow.

Moments before the light reached him, a being of many masks realised its mistake, and Merlin's.

He blurred into motion, all pretenses falling. Cursed fire consumed millenia old stones and diminished his body alike.

The world skipped and Harry was a foot to the left, silhouetted against a stone ceiling where only an eyeblink before there had been the open cloudless sky. Her eyes struggled to adjust to the low flickering light of the magical torches.

Her mind still worked, and it told her the pain was gone.

She flexed her toes, and heard the sheet that had been draped over her rustle in response.

She narrowed her eyes.

"What did you do, Harry?"

A wry smile crossed his face, although it stopped short of his glistening eyes.

"The only thing I could, Hermione."

AN:

I have edited the story a little to make the spell and some of Harry's thought process more explicit. The spell was never meant to be ambiguous, this is Reparo 2.0, where the fixus inanimatus objectus spell can extend to all things if the caster understands reality deeply enough.

The challenge for readers here, as per the HPMOR style, is to consider the implications. What happens next? Has Harry created a safe form of resurrection, unlocked the path to godhood or fulfilled the Divination teacher's prophecy, and if so, how? What will Quirrel do when he reaches the room and finds Hermione alive? If he intends harm, can Harry stop him?

The story is complete for now, although there are several alternate endings in my head. If anyone guesses them correctly I will write each one up.