Harry Potter and the Methods of Rationality

It was 2:45pm on Saturday and Harry Potter had half of Bathilda Bagshot's A History of Magic left to read and she was staring at her pocket watch as it ticked with dreadful slowness toward 2:47pm.

And the entire Ravenclaw common room was watching.

It wasn't just the first-years, news had spread like spilled milk and fully half of Ravenclaw was crowded into the room, squeezed into sofas and leaning on bookcases and sitting on the arms of chairs. All six prefects were there including the Head Girl of Hogwarts. Someone had needed to cast an Air-Freshening Charm just so that there would be enough oxygen. And the din of conversation had died into whispers which had now faded into utter silence.

2:46pm.

The tension was unbearable. If it had been anyone else, anyone else, his defeat would have been a foregone conclusion.

But this was Harry Potter, and you couldn't rule out the possibility that he would, sometime in the next few seconds, raise a hand and snap his fingers.

With sudden terror she realized how Harry Potter might be able to do exactly that. It would be just like him to have already finished reading the second half of the book earlier...

Hermione's vision began to swim. She tried to make herself breathe, and found that she simply couldn't.

Ten seconds left, and he still hadn't raised his hand.

Five seconds left.

2:47pm.

Harry Potter carefully placed a bookmark into his book, closed it, and laid it aside.

"I would like to note for the benefit of posterity," said the Boy-Who-Lived in a clear voice, "that I had only half a book left, and that I ran into a number of unexpected delays -"

"You lost!" shrieked Hermione. "You did! You lost our contest!"

There was a collective exhalation as everyone started breathing again.

Harry Potter shot her a Look of Flaming Fire, but she was floating in a halo of pure white happiness and nothing could touch her.

"Do you realize what kind of week I've had?" said Harry Potter. "Any lesser being would have been hard-pressed to read eight Dr. Seuss books!"

"You set the time limit."

Harry's Look of Flaming Fire grew even hotter. "I did not have any logical way of knowing I'd have to save the entire school from Professor Snape, or get beaten up in Defense class, and if I told you how I lost all the time between 5pm and dinner on Thursday you would think I was insane -"

"Awww, it sounds like someone fell prey to the planning fallacy."

Raw shock showed on Harry Potter's face.

"Oh that reminds me, I finished reading the first batch of books you lent me," Hermione said with her best innocent look. A couple of them had been hard books, too. She wondered how long it had taken him to finish reading them.

"Someday," said the Boy-Who-Lived, "when the distant descendants of Homo sapiens are looking back over the history of the galaxy and wondering how it all went so wrong, they will conclude that the original mistake was when someone taught Hermione Granger how to read."

"But you still lose," said Hermione. She held a hand to her chin and looked contemplative. "Now what exactly should you lose, I wonder?"

"What?"

"You lost the bet," Hermione explained, "so you have to pay a forfeit."

"I don't remember agreeing to this!"

"Really?" said Hermione Granger. She put a thoughtful look on her face. Then, as if the idea had only just then occurred to her, "We'll take a vote, then. Everyone in Ravenclaw who thinks Harry Potter has to pay up, raise your hand!"

"What?" shrieked Harry Potter again.

He spun around and saw that he was surrounded by a sea of raised hands.

And if Harry Potter had looked more carefully, he would have noticed that an awful lot of the onlookers seemed to be girls and that practically every female in the room had their hand raised.

"Stop!" wailed Harry Potter. "You don't know what she's going to ask! Don't you realize what she's doing? She's getting you to make an advance commitment now, and then the pressure of consistency will make you agree with whatever she says afterward!"

"Don't worry," said the prefect Penelope Clearwater. "If she asks for something unreasonable, we can just change our minds. Right, everyone?"

And there were eager nods from all the girls whom Penelope Clearwater had told about Hermione's plan.

A silent figure quietly slipped through the chilled halls of the Hogwarts dungeons. He was to be present in a certain room at 6:00pm to meet a certain someone, and if at all possible it was best to be early, to show respect.

But when his hand turned the doorknob and opened the door into that dark, silent, unused classroom, there was a silhouette already standing there amid the rows of dusty old desks. A silhouette which held a small green glowing rod, casting a pale light which hardly illuminated even he who held it, let alone the surrounding room.