Eliezer Yudkowsky - Harry Potter and the Methods of Rationality

It was Thursday for everyone, after all, and yet this sort of thing didn't seem to happen to anyone else.

It was 6:21pm on Thursday afternoon when Harry Potter, firing out of the stairwell like a cannonball and accelerating at top speed, ran directly into Minerva McGonagall as she was turning a corner on her way to the Headmaster's office.

Thankfully neither of them were much hurt. As had been explained to Harry a little earlier in the day - back when he was refusing to go anywhere near a broomstick again - Quidditch needed solid iron Bludgers just to stand a decent chance of injuring the players, since wizards tended to be a lot more resistant than Muggles to impacts.

Harry and Professor McGonagall did both end up on the floor, and the parchments she had been carrying went all over the corridor.

There was a terrible, terrible pause.

"Harry Potter," breathed Professor McGonagall from where she was lying on the floor right next to Harry. Her voice rose to nearly a shriek. " What were you doing in the Headmaster's office?"

"Nothing!" squeaked Harry.

"Were you talking about the Defence Professor?"

"No! Dumbledore called me up there and he gave me this big rock and said it was my father's and I should carry it everywhere!"

There was another terrible pause.

"I see," said Professor McGonagall, her voice a little calmer. She stood up, brushed herself off, and glared at the scattered parchments, which jumped into a neat stack and scurried back against the corridor wall as though to hide from her gaze. "My sympathies, Mr. Potter, and I apologise for doubting you."

"Professor McGonagall," Harry said. His voice was wavering. He pushed himself off the floor, stood, and looked up at her trustworthy, sane face. "Professor McGonagall..."

"Yes, Mr. Potter?"

"Do you think I should?" Harry said in a small voice. "Carry my father's rock everywhere?"

Professor McGonagall sighed. "That is between you and the Headmaster, I'm afraid." She hesitated. "I will say that ignoring the Headmaster completely is almost never wise. I am sorry to hear of your dilemma, Mr. Potter, and if there's any way I can help you with whatever you decide to do -"

"Um," Harry said. "Actually I was thinking that once I know how, I could Transfigure the rock into a ring and wear it on my finger. If you could teach me how to sustain a Transfiguration -"

"It is good that you asked me first," Professor McGonagall said, her face growing a bit stern. "If you lost control of the Transfiguration the reversal would cut off your finger and probably rip your hand in half. And at your age, even a ring is too large a target for you to sustain indefinitely without it being a serious drain on your magic. But I can have a ring forged for you with a setting for a jewel, a small jewel, in contact with your skin, and you can practice sustaining a safe subject, like a marshmallow. When you have kept it up successfully, even in your sleep, for a full month, I will allow you to Transfigure, ah, your father's rock..." Professor McGonagall's voice trailed off. "Did the Headmaster really - "

"Yes. Ah... um..."

Professor McGonagall sighed. "That's a bit strange even for him." She stooped and picked up the stack of parchments. "I'm sorry about this, Mr. Potter. I apologise again for mistrusting you. But now it's my own turn to see the Headmaster."

"Ah... good luck, I guess. Er..."

"Thank you, Mr. Potter."

"Um..."

Professor McGonagall walked over to the gargoyle, inaudibly spoke the password, and stepped through into the revolving spiral stairs. She began to rise out of sight, and the gargoyle started back -

" Professor McGonagall the Headmaster set fire to a chicken!"

"He wha- "

It was breakfast time on Friday morning. Harry took another huge bite out of his toast and then tried to remind his brain that scarfing his breakfast wouldn't actually get him into the dungeons any faster. Anyway they had a full hour of study time between breakfast and the start of Potions.

But dungeons! In Hogwarts! Harry's imagination was already sketching the chasms, narrow bridges, torchlit sconces, and patches of glowing moss. Would there be rats? Would there be dragons?

"Harry Potter," said a quiet voice from behind him.

Harry looked over his shoulder and found himself beholding Ernie Macmillan, smartly dressed in yellow-trimmed robes and looking a little worried.

"Neville thought I should warn you," Ernie said in a low voice. "I think he's right. Be careful of the Potions Master in our session today. The older Hufflepuffs told us that Professor Snape can be really nasty to people he doesn't like, and he doesn't like most people who aren't Slytherins. If you say anything smart to him it... it could be really bad for you, from what I've heard. Just keep your head down and don't give him any reason to notice you."

There was a pause as Harry processed this, and then he lifted his eyebrows. (Harry wished he could raise just one eyebrow, like Spock, but he'd never been able to manage.) "Thanks," Harry said. "You might've just saved me a lot of trouble."

Ernie nodded, and turned to go back to the Hufflepuff table.

Harry resumed eating his toast.

It was around four bites afterward that someone said "Pardon me," and Harry turned around to see an older Ravenclaw, looking a little worried -

Some time later, Harry was finishing up his third plate of rashers. (He'd learned to eat heavily at breakfast. He could always eat lightly at lunch if he didn't end up using the Time-Turner.) And there was yet another voice from behind him saying "Harry?"

"Yes," Harry said wearily, "I'll try not to draw Professor Snape's attention -"

"Oh, that's hopeless," said Fred.

"Completely hopeless," said George.

"So we had the house elves bake you a cake," said Fred.

"We're going to put one candle on it for every point you lose for Ravenclaw," said George.

"And have a party for you at the Gryffindor table during lunch," said Fred.

"We hope that'll cheer you up afterward," finished George.

Harry swallowed his last bite of rasher and turned around. "All right," said Harry. "I wasn't going to ask this after Professor Binns, I really wasn't, but if Professor Snape is that awful why hasn't he been fired?"

"Fired?" said Fred.

"You mean, let go?" said George.

"Yes," Harry said. "It's what you do to bad teachers. You fire them. Then you hire a better teacher instead. You don't have unions or tenure here, right?"

Fred and George were frowning in much the same way that hunter-gatherer tribal elders might frown if you tried to tell them about calculus.

"I don't know," said Fred after a while. "I never thought about that."

"Me neither," said George.

"Yeah," said Harry, "I get that a lot. See you at lunch, guys, and don't blame me if there aren't any candles on that cake."

Fred and George both laughed, as if Harry had said something funny, and bowed to him and headed back toward Gryffindor.

Harry turned back to the breakfast table and grabbed a cupcake. His stomach already felt full, but he had a feeling this morning might use a lot of calories.

As he ate his cupcake, Harry thought of the worst teacher he'd met so far, Professor Binns of History. Professor Binns was a ghost. From what Hermione had said about ghosts, it didn't seem likely that they were fully self-aware. There were no famous discoveries made by ghosts, or much of any original work, no matter who they'd been in life. Ghosts tended to have trouble remembering the current century. Hermione had said they were like accidental portraits, impressed into the surrounding matter by a burst of psychic energy accompanying a wizard's sudden death.