Eliezer Yudkowsky - Harry Potter and the Methods of Rationality

Harry nodded and continued. "So - suppose I had a way to get more Galleons from my vault without us going back to Gringotts, but it involved me violating the role of an obedient child. Would I be able to trust you with that, even though you'd have to step outside your own role as Professor McGonagall to take advantage of it?"

" What? " said Professor McGonagall.

"To put it another way, if I could make today have happened differently, so that we didn't take too little money with us, would that be all right even though it would involve a child being insolent to an adult in retrospect?"

"I... suppose..." the witch said, looking quite puzzled.

Harry took out the mokeskin pouch, and said, "Eleven Galleons originally from my family vault."

And there was gold in Harry's hand.

For a moment Professor McGonagall's mouth gaped wide, then her jaw snapped shut and her eyes narrowed and the witch bit out, " Where did you get that -"

"From my family vault, like I said."

" How? "

"Magic."

"That's hardly an answer!" snapped Professor McGonagall, and then stopped, blinking.

"No, it isn't, is it? I ought to claim that it's because I experimentally discovered the true secrets of how the pouch works and that it can actually retrieve objects from anywhere, not just its own inside, if you phrase the request correctly. But actually it's from when I fell into that pile of gold before and I shoved some Galleons into my pocket. Anyone who understands pessimism knows that money is something you might need quickly and without much warning. So now are you angry at me for defying your authority? Or glad that we succeeded in our important mission?"

The salesman's eyes were wide like saucers.

And the tall witch stood there, silent.

"Discipline at Hogwarts must be enforced," she said after almost a full minute. "For the sake of all the students. And that must include courtesy and obedience from you to all professors."

"I understand, Professor McGonagall."

"Good. Now let us buy that trunk and go home."

Harry felt like throwing up, or cheering, or fainting, or something . That was the first time his careful reasoning had ever worked on anyone . Maybe because it was also the first time he had something really serious that an adult needed from him, but still -

Minerva McGonagall, +1 point.

Harry bowed, and gave the bag of gold and the extra eleven Galleons into McGonagall's hands. "Thank you very much, Professor. Can you finish up the purchase for me? I've got to visit the lavatory."

The salesman, unctuous once more, pointed toward a door set into the wall with a gold-handled knob. As Harry started to walk away, he heard the salesman ask in his oily voice, "May I inquire as to who that was, Madam McGonagall? I take it he is Slytherin - third-year, perhaps? - and from a prominent family, but I did not recognise -"

The slam of the lavatory door cut off his words, and after Harry had identified the lock and pressed it into place, he grabbed the magical self-cleaning towel and, with shaky hands, wiped moisture off his forehead. Harry's entire body was sheathed in sweat which had soaked clear through his Muggle clothing, though at least it didn't show through the robes.

The sun was setting and it was very late indeed, by the time they stood again in the courtyard of the Leaky Cauldron, the silent leaf-dusted interface between magical Britain's Diagon Alley and the entire Muggle world. (That was one awfully decoupled economy...) Harry was to go to a phone box and call his father, once he was on the other side. He didn't need to worry about his luggage being stolen, apparently. His trunk had the status of a major magical item, something that most Muggles wouldn't notice; that was part of what you could get in the wizarding world, if you were willing to pay the price of a secondhand car.

"So here we part ways, for a time," Professor McGonagall said. She shook her head in wonderment. "This has been the strangest day of my life for... many a year. Since the day I learned that a child had defeated You-Know-Who. I wonder now, looking back, if that was the last reasonable day of the world."

Oh, like she had anything to complain about. You think your day was surreal? Try mine.

"I was very impressed with you today," Harry said to her. "I should have remembered to compliment you out loud, I was awarding you points in my head and everything."

"Thank you, Mr. Potter," said Professor McGonagall. "If you had already been sorted into a House I would have deducted so many points that your grandchildren would still be losing the House Cup."

"Thank you , Professor." It was probably too early to call her Minnie.

This woman might well be the sanest adult Harry had ever met, despite her lack of scientific background. Harry was even considering offering her the number-two position in whatever group he formed to fight the Dark Lord, though he wasn't silly enough to say that out loud. Now what would be a good name for that...? The Death Eater Eaters?

"I'll see you again soon, when school starts," Professor McGonagall said. "And, Mr. Potter, about your wand -"

"I know what you're going to ask," Harry said. He took out his precious wand and, with a deep twinge of inner pain, flipped it over in his hand, presenting her with the handle. "Take it. I hadn't planned to do anything, not a single thing, but I don't want you to have nightmares about me blowing up my house."

Professor McGonagall shook her head rapidly. "Oh no, Mr. Potter! That isn't done. I only meant to warn you not to use your wand at home, since the Ministry can detect underage magic and it is prohibited without supervision."

"Ah," Harry said. "That sounds like a very sensible rule. I'm glad to see the wizarding world takes that sort of thing seriously."

Professor McGonagall peered hard at him. "You really mean that."

"Yes," Harry said. "I get it. Magic is dangerous and the rules are there for good reasons. Certain other matters are also dangerous. I get that too. Remember that I am not stupid."

"I am unlikely ever to forget it. Thank you, Harry, that does make me feel better about entrusting you with certain things. Goodbye for now."

Harry turned to go, into the Leaky Cauldron and out towards the Muggle world.

As his hand touched the back door's handle, he heard a last whisper from behind him.

"Hermione Granger."

"What?" Harry said, his hand still on the door.

"Look for a first-year girl named Hermione Granger on the train to Hogwarts."

"Who is she?"

There was no answer, and when Harry turned around, Professor McGonagall was gone.

Aftermath:

Headmaster Albus Dumbledore leaned forward over his desk. His twinkling eyes peered out at Minerva. "So, my dear, how did you find Harry?"

Minerva opened her mouth. Then she closed her mouth. Then she opened her mouth again. No words came out.

"I see," Albus said gravely. "Thank you for your report, Minerva. You may go."

Petunia Evans-Verres's lips were trembling and her eyes were tearing up as Harry hugged her midsection on Platform Nine of the King's Cross Station. "Are you sure you don't want me to come with you, Harry?"

Harry glanced over to his father Michael Verres-Evans, who was looking stereotypically stern-but-proud, and then back to his mother, who really did look rather... uncomposed. "Mum, I know you don't like the wizarding world very much. You don't have to come with. I mean it."

Petunia winced. "Harry, you shouldn't worry about me, I'm your mother and if you need someone with you -"

"Mum, I'm going to be on my own at Hogwarts for months and months. If I can't manage a train platform alone, better to find out sooner rather than later so we can abort." He lowered his voice to a whisper. "Besides, Mum, they all love me over there. If I have any problems, all I need to do is take off my sweatband," Harry tapped the exercise band covering his scar, "and I'll have way more help than I can handle."