Eliezer Yudkowsky - Harry Potter and the Methods of Rationality

"You don't mean..." gasped Harry. "My father... owned another rock? "

"Excuse me," said Dumbledore, "I am still older and more mysterious than you and if there are any revelations to be made then I will do the revealing, thank you... oh, where is that thing!" Dumbledore reached down further into the desk drawer, and still further. His head and shoulders and whole torso disappeared inside until only his hips and legs were sticking out, as though the desk drawer was eating him.

Harry couldn't help but wonder just how much stuff was in there and what the complete inventory would look like.

Finally Dumbledore rose back up out of the drawer, holding the objective of his search, which he set down on the desk alongside the rock.

It was a used, ragged-edged, worn-spined textbook: Intermediate Potion Making by Libatius Borage. There was a picture of a smoking vial on the cover.

"This," Dumbledore intoned, "was your mother's fifth-year Potions textbook."

"Which I am to carry with me at all times," said Harry.

" Which holds a terrible secret . A secret whose revelation could prove so disastrous that I must ask you to swear - and I do require you to swear it seriously, Harry, whatever you may think of all this - never to tell anyone or anything else."

Harry considered his mother's fifth-year Potions textbook, which, apparently, held a terrible secret.

The problem was that Harry did take that oaths like that very seriously. Any vow was an Unbreakable Vow if made by the right sort of person.

And...

"I'm feeling thirsty," Harry said, "and that is not at all a good sign."

Dumbledore entirely failed to ask any questions about this cryptic statement. " Do you swear, Harry?" said Dumbledore. His eyes gazed intently into Harry's. "Otherwise I cannot tell you."

"Yes," said Harry. "I swear." That was the trouble with being a Ravenclaw. You couldn't refuse an offer like that or your curiosity would eat you alive, and everyone else knew it.

"And I swear in turn," said Dumbledore, "that what I am about to tell you is the truth."

Dumbledore opened the book, seemingly at random, and Harry leaned in to see.

"Do you see these notes," Dumbledore said in a voice so low it was almost a whisper, "written in the margins of the book?"

Harry squinted slightly. The yellowing pages seemed to be describing something called a potion of eagle's splendour, many of the ingredients being items that Harry didn't recognise at all and whose names didn't appear to derive from English. Scrawled in the margin was a handwritten annotation saying, I wonder what would happen if you used Thestral blood here instead of blueberries? and immediately beneath was a reply in different handwriting, You'd get sick for weeks and maybe die.

"I see them," said Harry. "What about them?"

Dumbledore pointed to the second scrawl. "The ones in this handwriting," he said, still in that low voice, "were written by your mother. And the ones in this handwriting," moving his finger to indicate the first scrawl, "were written by me. I would turn myself invisible and sneak into her dorm room while she was sleeping. Lily thought one of her friends was writing them and they had the most amazing fights."

That was the exact point at which Harry realised that the Headmaster of Hogwarts was, in fact, crazy.

Dumbledore was looking at him with a serious expression. "Do you understand the implications of what I have just told you, Harry?"

"Ehhh..." Harry said. His voice seemed to be stuck. "Sorry... I... not really..."

"Ah well," said Dumbledore, and sighed. "I suppose your cleverness has limits after all, then. Shall we all just pretend I didn't say anything?"

Harry rose from his chair, wearing a fixed smile. "Of course," Harry said. "You know it's actually getting rather late in the day and I'm a bit hungry, so I should be going down to dinner, really" and Harry made a beeline for the door.

The doorknob entirely failed to turn.

"You wound me, Harry," said Dumbledore's voice in quiet tones that were coming from right behind him. "Do you not at least realise that what I have told you is a sign of trust?"

Harry slowly turned around.

In front of him was a very powerful and very insane wizard with a long silver beard, a hat like a squashed giant mushroom, and wearing what looked to Muggle eyes like three layers of bright pink pyjamas.

Behind him was a door that didn't seem to be working at the moment.

Dumbledore was looking rather saddened and weary, like he wanted to lean on a wizard's staff he didn't have. "Really," said Dumbledore, "you try anything new instead of following the same pattern every time for a hundred and ten years, and people all start running away." The old wizard shook his head in sorrow. "I'd hoped for better from you, Harry Potter. I'd heard that your own friends also think you mad. I know they are mistaken. Will you not believe the same of me?"

"Please open the door," Harry said, his voice trembling. "If you ever want me to trust you again, open the door."

There was the sound behind him of a door opening.

"There were more things I planned to say to you," Dumbledore said, "and if you leave now, you will not know what they were."

Sometimes Harry absolutely hated being a Ravenclaw.

He's never hurt a student, said Harry's Gryffindor side. Just keep remembering that and you'll be sure not to panic. You're not going to run away just because things are getting interesting, are you?

You can't just walk out on the Headmaster! said the Hufflepuff part. What if he starts deducting House points? He could make your school life very difficult if he decides he doesn't like you!

And a piece of himself which Harry didn't much like but couldn't quite manage to silence was pondering the potential advantages of being one of the few friends of this mad old wizard who also happened to be Headmaster, Chief Warlock, and Supreme Mugwump. And unfortunately his inner Slytherin seemed to be much better than Draco at turning people to the Dark Side, because it was saying things like poor fellow, he looks like he needs someone to talk to, doesn't he? and you wouldn't want such a powerful man to end up trusting someone less virtuous, would you? and I wonder what sort of incredible secrets Dumbledore could tell you if, you know, you became friends with him and even I bet he's got a reaallly interesting book collection.

You're all a bunch of lunatics, Harry thought at the entire assemblage, but he'd been unanimously outvoted by every component part of himself.

Harry turned, took a step towards the open door, reached out, and deliberately closed it again. It was a costless sacrifice given that he was staying anyway, Dumbledore could control his movements regardless, but maybe it would impress Dumbledore.

When Harry turned back around he saw that the powerful insane wizard was once more smiling and looking friendly. That was good, maybe.

"Please don't do that again," Harry said. "I don't like being trapped."

"I am sorry about that, Harry," said Dumbledore in what sounded like tones of sincere apology. "But it would have been terribly unwise to let you leave without your father's rock."

"Of course," Harry said. "It wasn't reasonable of me to expect the door to open before I put the quest items in my inventory."

Dumbledore smiled and nodded.

Harry went over to the desk, twisted his mokeskin pouch around to the front of his belt, and, with some effort, managed to heave up the rock in his eleven-year-old arms and feed it in.

He could actually feel the weight slowly diminishing as the Widening Lip charm ate the rock, and the burp which followed was rather noisy and had a distinctly complaining sound to it.