Eliezer Yudkowsky - Harry Potter and the Methods of Rationality

" Professor Flitwick, don't let Harry try, send him back! "

The Headmaster had arrived by then, and he and Professor Flitwick were exchanging worried looks.

"I did not hear the Dementor speak," the Headmaster said. "Still..."

"Just ask," said Professor Quirrell, sounding a little weary.

"Did the Dementor say how it would get to Harry?" said the Headmaster.

"All his tastiest parts first," said Hermione, "it would - it would eat -"

Hermione blinked. Some sanity seemed to come back into her eyes.

Then she started crying.

"You were too brave, Hermione Granger," the Headmaster said. His voice was gentle, and clearly audible. "Too much braver than I comprehended. You should have turned and run, not endured and tried to complete your Charm. When you are older and stronger, Miss Granger, I know that you will try again, and I know that you will succeed."

"I'm sorry," Hermione said in gasps, "I'm sorry, I'm sorry, I'm sorry... I'm sorry, Harry, I can't tell you what I saw, I didn't look at it, I didn't dare look at it, I knew it was too horrible to ever be seen..."

It should have been Harry, but he'd hesitated, because his hands were all chocolatey; and then Ernie and Susan were there, helping Hermione from where she'd fallen on the grass, leading her toward the snacks table.

Five bars of chocolate later, Hermione seemed to be all right again, and she went over and apologized to Professor Quirrell; but she was always watching Harry, every time that he glanced in her direction. He'd stepped toward her only once, and stopped when she'd stepped away. Her eyes had silently apologized, and silently pleaded for him to leave her be.

Neville Longbottom had seen something dead and half-dissolved, oozing and running with a face like a squashed sponge.

It was the worst thing anyone had yet described seeing. Neville had been able to produce a small flicker of light from his wand before, but he had, intelligently and with great presence of mind, turned and run away instead of trying to cast his own Patronus Charm.

(The Headmaster had said nothing to the other students, told no one else to be less brave; but Professor Quirrell had calmly observed that if you made the mistake after being warned, that was when ignorance became stupidity.)

"Professor Quirrell?" Harry said in a low voice, having come as close to the Defense Professor as he dared. "What do you see when you -"

"Don't ask." The voice was very flat.

Harry nodded respectfully. "What was your original phrasing to the Headmaster, if I can ask?"

Dryly. "Our worst memories can only grow worse as we grow older."

"Ah," Harry said. "Logical."

Something strange flickered in Professor Quirrell's eyes, then, as he looked at Harry. "Let us hope," Professor Quirrell said, "that you succeed upon this try, Mr. Potter. For if you do, the Headmaster may teach you his trick of using a Patronus to send messages that cannot be forged or intercepted, and the military importance of that is impossible to overstate. It would be a tremendous advantage to the Chaos Legion, and someday, I suspect, this entire country. But if you do not succeed, Mr. Potter... well, I shall understand."

Morag MacDougal had said, in a wavering voice, "Ouch", and Dumbledore had recast his Patronus right away.

Parvati Patil had produced a corporeal Patronus in the form of a tiger, larger than Dumbledore's phoenix, though not nearly as bright. There had been a great burst of applause from all the watchers, though not the same shock as when Anthony had done it.

And then it was Harry's turn.

The Headmaster called the name of Harry Potter, and Harry was afraid.

Harry knew, he knew that he was going to fail, and he knew that it was going to hurt.

But he still had to try; because sometimes, in the presence of a Dementor, a wizard went from not a flicker of light to a full corporeal Patronus, and no one understood why.

And because if Harry couldn't defend himself from Dementors, he had to be able to recognize their approach, recognize the feeling of them in his mind, and run before it was too late.

What is my worst memory...?

Harry had expected the Headmaster to give him a worried look, or a hopeful look, or deeply wise advice; but instead Albus Dumbledore only watched him with quiet calm.

He thinks I'm going to fail, but he won't sabotage me by telling me so, thought Harry, if he had true words of encouragement to speak, he would speak them...

The cage came closer. It was already tarnished, but not rusted away to nothing, not yet.

The cloak came closer. It was unraveling and shot through with unpatched holes; it had been new that morning, Auror Goryanof had said.

"Headmaster?" Harry said. "What do you see?"

The Headmaster's voice was also calm. "The Dementors are creatures of fear, and as your fear of the Dementor diminishes, so does the fearsomeness of its form. I see a tall, thin, naked man. He is not decaying. He is only slightly painful to look upon. That is all. What do you see, Harry?"

...Harry couldn't see under the cloak.

Or that wasn't right, it was that his mind was refusing to see what was under the cloak...

No, his mind was trying to see the wrong thing under the cloak, Harry could feel it, his eyes trying to force a mistake. But Harry had done his best to train himself to notice that tiny feeling of confusion, to automatically flinch away from making stuff up; and every time his mind tried to start inventing a lie about what was under the cloak, that reflex was fast enough to shut it down.

Harry looked under the cloak and saw...

An open question. Harry wouldn't let his mind see something false, and so he didn't see anything, like the part of his visual cortex getting that signal was just ceasing to exist. There was a blind spot under the cloak. Harry couldn't know what was under there.

Just that it was far worse than any decaying mummy.

The unseeable horror beneath the cloak was very close, now, but the blazing bird of moonlight, the white phoenix, yet lay between them.

Harry wanted to run away like some of the other students had. Half the ones who'd had no luck with their Patronus Charms just hadn't shown up today in the first place. Of those remaining, half had fled before the Headmaster had even dispelled his own Patronus, and no one had said a word. There'd been a little laughter when Terry had turned and walked back before his own try; and Susan and Hannah, who'd gone before, had yelled at everyone to shut up.

But Harry was the Boy-Who-Lived, and he would lose much respect if he was seen to give up without even trying...

Pride and roles seemed to diminish and fall away, in the presence of whatever lay beneath the cloak.

Why am I still here?

It wasn't the shame of others thinking him cowardly, that kept Harry's feet in place.

It wasn't the hope of repairing his reputation that brought up his wand.

It wasn't the desire to master the Patronus Charm as magic, that moved his fingers into the initial position.

It was something else, something that had to oppose whatever lay beneath the cloak, this was the true darkness and Harry had to find out whether it lay within him, the power to drive it back.

Harry had planned to try one final time to think of his book-shopping spree with his father, but instead, at the last minute, facing the Dementor, a different memory occurred to him, something he hadn't tried before; a thought that wasn't warm and happy in the ordinary way, but felt righter, somehow.

And Harry remembered the stars, remembered them burning terribly bright and unwavering in the Silent Night; he let that image fill him, fill all of him like an Occlumency barrier across his entire mind, became once again the bodiless awareness of the void.