Eliezer Yudkowsky - Harry Potter and the Methods of Rationality

“It’s time,” Harry murmured to the empty air, and began walking down the third-floor corridor above the grand staircase, on the righthand side.

‘The place that is prohibited’ would ordinarily mean the Forbidden Forest; that was probably what someone intercepting the message was meant to think. But the Forbidden Forest was huge, and there was more than one distinguished location inside it. No obvious Schelling Point at which to rendezvous, or find some event that needed intervention.

But when you added the ‘bloody stupid’ modifier, there was only one prohibited place in Hogwarts that fit.

And so Harry set forth on that outlawed path where, if rumor spoke true, all the first-year Gryffindors had gone before. The third-floor corridor, on the right-hand side. A mysterious door leading to a series of rooms filled with dangerous and potentially lethal traps that nobody could possibly get through, especially if they were only in their first year.

Harry didn’t know himself what sort of traps awaited. Which, on reflection, meant that the students who’d gone through had been surprisingly scrupulous about not ruining the puzzle for others. Maybe there was a sign down there saying Don’t give it away, just as a favor to me, sincerely Headmaster Dumbledore . All Harry knew so far was that the outer door would open to Alohomora, and that the final room contained a magic mirror that would show your reflection in some situation you found highly appealing, which was apparently the big payoff.

The third-floor corridor was illuminated by dim blue light that seemed to come from nowhere, and the arches were covered with cobwebs, as though the corridor hadn’t been used in centuries rather than just the last year.

Harry’s pouch was loaded with useful Muggle things, and useful wizarding things, and everything he’d found that could possibly be a quest item. (Harry had asked Professor McGonagall to recommend someone who could expand the pouch’s capacity, and she’d just done it herself.) Harry had applied the Charm he’d learned for battles that made his eyeglasses stick to his face, regardless of how his head moved. Harry had refreshed the Transfigurations he was maintaining, both the tiny jewel in the ring on his hand and the other one, in case he was knocked unconscious. He wasn’t literally ready for anything, but Harry was as ready as he thought he could be.

The five-sided floor tiles creaked beneath Harry’s shoes and vanished behind him like the future becoming the past. It was almost 6:49— six, and seven in a square. Obvious if you thought in Muggle math, otherwise not so much.

Just as Harry was about to round another corner, something tickled at the back of his mind, and he heard a soft voice talking.

“…sensible person… wait until later… after certain faculty had departed…”

Harry stopped, then crept forward as lightly as he could, not going around the corner, trying to hear Professor Quirrell’s voice better.

There came a louder cough, and then the soft voice spoke again from around the corner. “But if they were also… to depart themselves… at that time…” murmured the voice, “they might think… this final game… makes for the best distraction… left in this year… a predictable distraction. So I looked… to see what people of significance… were not at the game… and I saw the Headmaster missing… but for all my magic can tell me… he could be in another… realm of existence… I also saw your own absence… so I decided to go… where you were. That is what I am doing here… now… what are you doing here?”

Harry breathed shallowly, and listened.

“And just how did you know where I was?” drawled the voice of Severus Snape, so much louder that Harry nearly jumped.

A small, coughing laugh. “Check your wand… for Trace.”

Severus said something in magical pseudo-Latin, and then, “You dared tamper with my wand? You dared? ”

“You are a suspect… just like myself… so your false indignation is wasted… however finely crafted it may be… now tell me… what are you doing?”

“I am watching this door,” said the voice of Professor Snape. “And I will ask you to be off from it!”

“On whose authority… are you ordering me… my fellow Professor?”

There was a pause, then, “Why, the Headmaster’s,” came the smooth voice of Severus Snape. “I was ordered by him to watch this door during the Quidditch match, and as a Professor I must obey his whims. I shall have words about it with the Board of Governors later, but for now I am doing as I must. Now be off with you, as the Headmaster desires.”

“What? You mean I am to believe… that you abandoned your Slytherins… during their most important… game of the year… and leapt up like a dog… at Dumbledore’s word? Well that… I must say… is entirely plausible. Even so… I think it would be wise… if I kept my own watch over you.. while you watch this fine door.” There was a sound of rustling cloth and a soft thud, as if someone had sat down hard upon the ground, or maybe just fallen.

“Oh, for the love of Merlin—” Severus Snape’s voice now sounded angry. “Get up, you!”

“Ba-blu-a-bu-bluh—” said the Defense Professor’s zombie-mode.

“Get up!” said Severus Snape, and there was a soft thud.

Help the watcher of stars—

Harry stepped around the corner, though it was possible that he’d have done so even without an intertemporal message. Had Professor Snape just kicked Professor Quirrell? That would have been foolhardy if Professor Quirrell had been dead and buried.

A round-topped door of dark wood was framed within a stone arch, set within the dusty marble bricks of Hogwarts. Where a Muggle would have set a doorknob there was only a handle of polished metal; there were no visible locks, or visible keyholes. Set upon the wall to either side, a pair of torches burned, sending forth an ominous orange glow. Before the door stood the Potions Master in his customary stained robes. Beside the door, to the left side beneath the orange torch, slumped the form of the Defense Professor, back against the wall, head staring out at the surroundings. The eyes seemed to flicker, as if halfway between awareness, and emptiness.

“ What ,” said the towering form of the Potions Master, “are you doing here, Potter? ”

Going by facial expressions and tone of voice, the Potions Master was quite angry with Harry; and certainly was not Harry’s co-conspirator in councils to which the Defense Professor had never been invited.

“I’m not sure,” Harry said. He wasn’t sure what role he should be playing, and was, in desperation, falling back on simple honesty. “I think perhaps I’m supposed to be keeping an eye on the Defense Professor.”

The Potions Master stared at him coldly. “Where’s your escort, Potter? Students are not to wander these halls alone!”

Harry’s mind was genuinely blank. The game was afoot, and nobody had told him the rules. “I’m not sure how to answer that…”

The cold expression on Professor Snape’s face flickered. “Perhaps I should call the Aurors,” he said.

“Wait!” Harry blurted.

The Potions Master’s hand hovered about his robes. “Why?” said the Potions Master.

“I… I just think you probably shouldn’t call them…”

In a blur, the Potions Master’s wand was in his hand. “ Nullus confundio! ” A black jet darted out and hit Harry, striking in the direction Harry had already started to evade. There followed four other spells, containing words like Polyfluis and Metamorphus; and for those Harry politely stood still.