Harry Potter and the Methods of Rationality

"You fools!" shouted Lucius Malfoy. The white hair was shaking as though in a wind, the face beneath was pale with fury. "Do you think you'll get away with what you've done today? Do you think that girl can try to murder my son and escape unscathed?"

The toad-like pink-makeup woman, whose name Harry could no longer remember, was standing up from her seat. "Why, of course not," she said with a sickening smile. "After all, the girl is still a murderess, and I think the Ministry shall be watching her affairs quite closely - it hardly seems wise that she should be allowed to wander the streets, after all -"

Harry was fed up at this point.

Without waiting to listen, Harry turned on his heel and strode forward in long steps toward -

The horror only he could truly see, the absence of color and space, the wound in the world, above which floated a tattered cloak; most imperfectly guarded by a running moonlit squirrel and fluttering silver sparrow.

His dark side had also noticed, when it was looking through the entire room for anything that could possibly be used as a weapon, that the enemy had been foolish enough to bring a Dementor into Harry's presence. That was a powerful weapon indeed, and one that Harry might wield better than its supposed masters. There had been a time in Azkaban when Harry had told twelve Dementors to turn and go, and they had gone.

The Dementors are Death, and the Patronus Charm works by thinking about happy thoughts instead of Death.

If Harry's theory was correct, that one sentence would be all it took to pop the Aurors' Patronus Charms like a soap bubble, and ensure that nobody within reach of his voice could cast another one.

I am going to cancel the Patronus Charms and prevent any more Patronuses from being cast. And then my Dementor, flying faster than any broomstick, is going to Kiss everyone here who voted to send a twelve- year-old girl to Azkaban.

Say that, to set up the if-then expectation, and wait for people to understand and laugh. Then speak the fatal truth; and when the Aurors' Patronuses winked out to prove the point, either people's anticipations of the mindless void, or Harry's threat of its destruction, would make the Dementor obey. Those who had sought to compromise with the darkness would be consumed by it.

It was the other solution his dark side had devised.

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.

In the hall there was a deathly silence.

Harry turned his back on the empty void, and looked up at where the toad-woman stood. She was pale beneath the pink makeup, her mouth opening and closing like a fish.

"I make you this one offer," said the Boy-Who-Lived. "I never learn that you've been interfering with me or any of mine. And you never find out why the unkillable soul-eating monster is scared of me. Now sit down and shut up."

The toad-woman fell back down to her bench without a word.

Harry looked further up.

"A riddle, Lord Malfoy!" the Boy-Who-Lived shouted across the Most Ancient Hall. "I know you weren't in Ravenclaw, but try to answer this one anyway! What destroys Dark Lords, frightens Dementors, and owes you sixty thousand Galleons?"

For an instant Lord Malfoy stood there with eyes slightly widened; then his face fell back into calm scorn, and his voice spoke coolly in reply. "Are you openly threatening me, Mr. Potter?"

"I'm not threatening you," said the Boy-Who-Lived. "I'm scaring you. There's a difference."

"Enough, Mr. Potter," said Professor McGonagall. "We shall be late for afternoon Transfiguration as it is. And do come back here, you're still terrifying that poor Dementor." She turned to the Aurors. "Mr. Kleiner, if you would!"

Harry strode back to them, as the Auror addressed moved forward and pressed a short rod of dark metal to the dark metal chair, muttering an inaudible word of dismissal.

The chains slithered back as smoothly as they had come forth; and Hermione pushed herself out of the chair as fast as she could, and half-ran and half-staggered forward a few steps.

Harry held out his arms -

- and Hermione half-jumped half-fell into Professor McGonagall's arms, beginning to sob hysterically.

Hmpfh, said a voice inside Harry. I kind of thought we'd earned that one ourselves.

Oh, shut up.