Eliezer Yudkowsky - Harry Potter and the Methods of Rationality

"How's it doing?" said Fred in a low voice.

(Not that there'd be anyone listening, but there was something odd about talking in a normal voice when you were going through a secret passage.)

"Still on the fritz," said George.

"Both, or -"

"Intermittent one fixed itself again. Other one's same as ever."

The Map was an extraordinarily powerful artifact, capable of tracking every sentient being on the school grounds, in real time, by name. Almost certainly, it had been created during the original raising of Hogwarts. It was not good that errors were starting to pop up. Chances were that no one except Dumbledore could fix it if it was broken.

And the Weasley twins weren't about to turn the Map over to Dumbledore. It would have been an unforgivable insult to the Marauders - the four unknowns who'd managed to steal part of the Hogwarts security system , something probably forged by Salazar Slytherin himself, and twist it into a tool for student pranking .

Some might have considered it disrespectful.

Some might have considered it criminal.

The Weasley twins firmly believed that if Godric Gryffindor had been around to see it, he would have approved.

The brothers walked on and on and on, mostly in silence. The Weasley twins talked to each other when they were thinking through new pranks, or when one of them knew something the other didn't. Otherwise there wasn't much point. If they already knew the same information, they tended to think the same thoughts and make the same decisions.

(Back in the old days, whenever magical identical twins were born, it had been the custom to kill one of them after birth.)

In time, Fred and George clambered out into a dusty cellar, strewn with barrels and racks of strange ingredients.

Fred and George waited. It wouldn't have been polite to do anything else.

Before too long a thin old man in black pajamas clambered down the steps that led into the cellar, yawning. "Hello, boys," said Ambrosius Flume. "I wasn't expecting you tonight. Out of stock already?"

Fred and George decided that Fred would speak.

"Not exactly, Mr. Flume," said Fred. "We were hoping you could help us with something considerably more... interesting."

"Now, boys," said Flume, sounding severe, "I hope you didn't wake me up just so I could tell you again that I'm not selling you any merchandise that could get you into real trouble. Not until you're sixteen, anyways -"

George drew forth an item from his robes, and wordlessly passed it to Flume. "Have you seen this?" said Fred.

Flume looked at yesterday's edition of the Daily Prophet and nodded, scowling. The headline on the paper read THE NEXT DARK LORD? and showed a young boy which some student's camera had managed to catch in an uncharacteristically cold and grim expression.

"I can't believe that Malfoy," Flume snapped. "Going after the boy when he's only eleven! The man ought to be ground up and used to make chocolates!"

Fred and George blinked in unison. Malfoy was behind Rita Skeeter? Harry Potter hadn't warned them about that... which surely meant that Harry didn't know. He never would have brought them in if he did...

Fred and George exchanged glances. Well, Harry didn't need to know until after the job was done.

"Mr. Flume," Fred said quietly, "the Boy-Who-Lived needs your help."

Flume looked at them both.

Then he let out his breath with a sigh.

"All right," said Flume, "what do you want?"

Act 6:

When Rita Skeeter was intent on a tasty prey, she didn't tend to notice the scurrying ants who constituted the rest of the universe, which was how she almost bumped into the balding young man who'd stepped into her pathway.

"Miss Skeeter," said the man, sounding rather severe and cold for someone whose face looked that young. "Fancy running into you here."

"Out of my way, buster!" snapped Rita, and tried to step around him.

The man in her pathway matched the movement so perfectly that it was like neither of them had moved at all, just stood still while the street shifted around them.

Rita's eyes narrowed. "Who do you think you are?"

"How very foolish," the man said dryly. "It would have been wise to memorize the face of the disguised Death Eater training Harry Potter to be the next Dark Lord. After all," a thin smile, " that certainly sounds like someone you wouldn't want to run into on the street, especially after doing a hatchet job on him in the newspaper."

Rita took a moment to place the reference. This was Quirinus Quirrell? He looked too young and too old at the same time; his face, if it relaxed from its severe and condescending pose, would belong to someone in his late thirties. And his hair was already falling out? Couldn't he afford a healer?

No, that wasn't important, she had a time and a place and a beetle to be. She'd just received an anonymous tip about Madam Bones making time with one of her younger assistants. That would be worth quite a bonus if she could manage to verify it, Bones was high on the hit list. The tipster had said that Bones and her young assistant were due to eat lunch in a special room at Mary's Place, a very popular room for certain purposes; a room which, she'd found, was secure against all listening devices, but not proof against a beautiful blue beetle nestled up against one wall...

"Out of my way! " Rita said, and tried to push Quirrell from her path. Quirrell's arm brushed her own, deflecting, and Rita staggered as the thrust went into the thin air.

Quirrell pulled up the sleeve of his left robe, showing his left arm. "Observe," said Quirrell, "no Dark Mark. I would like your paper to publish a retraction."

Rita let out an incredulous laugh. Of course the man wasn't a real Death Eater. The paper wouldn't have published it if he was. "Forget it, buster. Now take a hike."

Quirrell stared at her for a moment.

Then he smiled.

"Miss Skeeter," said Quirrell, "I had hoped to find some lever that would prove persuasive. Yet I find that I cannot deny myself the pleasure of simply crushing you."

"It's been tried. Now get out of my way, buster, or I'll find some Aurors and have you arrested for obstruction of journalism."

Quirrell swept her a small bow, and then walked past. "Goodbye, Rita Skeeter," said his voice from behind her.

As Rita bulled on ahead, she noted in the back of her mind that the man was whistling a tune as he walked away.

Like that would scare her.

Act 4:

"Sorry, count me out," said Lee Jordan. "I'm more the giant spider type."

The Boy-Who-Lived had said that he had important work for the Order of Chaos, something serious and secret, more significant and difficult than their usual run of pranks.

And then Harry Potter had launched into a speech that was inspiring, yet vague. A speech to the effect that Fred and George and Lee had tremendous potential if they could just learn to be weirder. To make people's lives surreal, instead of just surprising them with the equivalents of buckets of water propped above doors. (Fred and George had exchanged interested looks, they'd never thought of that one.) Harry Potter had invoked a picture of the prank they'd pulled on Neville - which, Harry had mentioned with some remorse, the Sorting Hat had chewed him out on - but which must have made Neville doubt his own sanity. For Neville it would have felt like being suddenly transported into an alternate universe. The same way everyone else had felt when they'd seen Snape apologize. That was the true power of pranking.

Are you with me? Harry Potter had cried, and Lee Jordan had answered no.

"Count us in ," said Fred, or possibly George, for there was no doubt that Godric Gryffindor would have said yes.