Eliezer Yudkowsky - Harry Potter and the Methods of Rationality

“As one of my questions you said you’d answer, I ask how to cast that spell,” Harry said.

“Denied.” The Defense Professor turned back to his potion, dropping in a gray-flecked white feather and a bellflower. “I had thought perhaps to teach you when you were older, for no Tom Riddle would be content otherwise; but I have changed my mind.”

Memory is a hard thing to recall, sometimes, and Harry had been trying to remember if Professor Quirrell had dropped any hints about this subject before. Something about Professor Quirrell’s phrasing sparked a memory: Perhaps you will be told when you are older…

“There are still physical anchors for your immortality,” Harry said aloud. “It resembles the old horcrux spell by that much, which is another reason you still call them horcruxes.” It was dangerous to say aloud, but Harry needed to know. “If I’m wrong, you can always deny it in Parseltongue.”

Professor Quirrell was smiling evilly. “ Your guesss iss right, boy, for all the good it doess you. ”

Unfortunately, that wasn’t a difficult vulnerability to cover if the Enemy was smart. Harry wouldn’t ordinarily have made the suggestion, just in case the Enemy hadn’t thought of it for themselves, but in this case he’d already made it. “One horcux dropped into an active volcano, weighted so it would sink into the Earth’s mantle,” Harry said heavily. “The same place I thought of dropping the Dementor if I couldn’t destroy it. And then you asked me where else I would hide something if I didn’t want anyone to find it ever again. One horcrux buried kilometers down, in an anonymous cubic meter of the Earth’s crust. One horcrux you dropped into the Mariana Trench. One horcrux floating high in the stratosphere, transparent. Even you don’t know where they are, because you Obliviated the exact details from your memory. And the last horcrux is the Pioneer 11 plaque that you snuck into NASA and modified. It’s where you get your image of the stars, when you cast the spell of starlight. Fire, earth, water, air, void.” Something of a riddle, the Defense Professor had called it, and therefore Harry had remembered it. Something of a Riddle.

“Indeed,” said the Defense Professor. “It did give me something of a shock when you remembered it that quickly, but I suppose it makes no difference; all five are beyond my reach, or yours.”

That might not be true, especially if there was some way to trace the magical connection somehow and determine the location… though presumably Voldemort would have done his best to obscure it… but what magic had done, magic might be able to defeat. Pioneer 11 might be far away by wizard standards, but NASA knew exactly where it was, and it was probably a lot more reachable if you could use magic to tell the Tsiolkovsky rocket equation to bugger off…

A sudden note of worry plucked at Harry’s mind. There was no rule saying the Defense Professor needed to have told the truth about which interstellar probe he’d horcruxed, and if Harry recalled correctly, communication and tracking of the Pioneer 10 probe had been lost shortly after the Jupiter fly-by.

Why wouldn’t Professor Quirrell have just horcruxed them both?

The obvious next thought came to Harry. It was something that ought not to be suggested, if the Enemy had not thought of it. But it seemed extremely probable that the Enemy had thought of it.

“ Tell me, teacher, ” Harry hissed, “ would desstroying thosse five anchors sslay you? ”

“ Why do you assk? ” hissed the Defense Professor, with a lilt to the hiss that Parseltongue translated as snakish amusement. “ Do you ssusspect that ansswer is no? ”

Harry couldn’t think of how to answer, though he strongly suspected that it didn’t matter in any case.

“ Your ssusspicion iss right, boy. Desstroying thosse five would not render me mortal. ”

Harry’s throat felt a bit dry again. If the spell had no disastrous cost associated with it… “ How many anchorss did you make? ”

“ Would not ordinarily ssay, but iss clear you have already guesssed. ” The Defense Professor’s smile widened. “ Ansswer iss that I do not know. Sstopped countingssomewherearoundonehundredandsseven. Ssimplymadeahabitofiteach time I murdered ssomeone in private. ”

Over one hundred murders, in private, before Lord Voldemort had stopped counting. And even worse news—“Your immortality spell still requires a human death? Why? ”

“ Great creation maintainss life and magic within devicess created by ssacrificing life and magic of otherss. ” Again that hissing snake laughter. “ Liked falsse desscription of previousss horcrux sspell sso much, sso dissappointed when realissed truth of it, thoughtss of improved verssion came out in that sshape. ”

Harry wasn’t sure why the Defense Professor was giving him all this vital information, but there had to be a reason, and that was making him nervous. “So you really are a disembodied spirit possessing Quirinus Quirrell.”

“ Yess. I sshall return sswiftly, if thiss body iss killed. Will be greatly annoyed, and vengeful. I am telling you this, boy, so that you do not try anything stupid.”

“I understand,” Harry said. He did his best to organize his thoughts, remember what he’d meant to ask next, while the Defense Professor turned his eyes back to the potion. The man’s left hand was dribbling crushed seashell into the cauldron, while his right hand dropped in another bellflower. “So what did happen on October 31st? You… tried to turn the baby Harry Potter into a horcrux, either the new kind or the old kind. You did it deliberately, because you told Lily Potter,” Harry took a breath. Now that he knew why the chills were there, he could endure them. “Very well, I accept the bargain. Yourself to die, and the child to live. Now drop your wand so that I can murder you.” In retrospect, it was clear that Harry had remembered that event mainly from Lord Voldemort’s perspective, and only at the very end had he seen it through the baby Harry Potter’s eyes. “What did you do? Why did you do it?”

“Trelawney’s prophecy,” Professor Quirrell said. His hand tapped a bellflower with a strip of copper before dropping it in. “I spent long days pondering it, after Snape brought the prophecy to me. Prophecies are never trivial things. And how shall I put this in a way that does not make you think stupid things… well, I shall say it, and if you are stupid I shall be annoyed. I was fascinated by the prophecy’s assertion that someone would be my equal, because it might mean that person could hold up the other end of an intelligent conversation. After fifty years of being surrounded by gibbering stupidity, I no longer cared whether my reaction might be considered a literary cliche. I was not about to pass up on that opportunity without thinking about it first. And then, you see, I had a clever idea .” Professor Quirrell sighed. “It occurred to me how I might fulfill the Prophecy my own way, to my own benefit. I would mark the baby as my equal by casting the old horcrux spell in such fashion as to imprint my own spirit onto the baby’s blank slate; it would be a purer copy of myself, since there would be no old self to mix with the new. In some years, when I had become bored with ruling Britain and moved on to other things, I would arrange with the other Tom Riddle that he should appear to vanquish me, and he would rule over the Britain he had saved. We would play the game against each other forever, keeping our lives interesting amid a world of fools. I knew a dramatist would predict that the two of us would end by destroying each other; but I pondered long upon it, and decided that both of us would simply decline to play out the drama. That was my decision and I was confident that it would remain so; both Tom Riddles, I thought, would be too intelligent to truly go down that road. The prophecy seemed to hint that if I destroyed all but a remnant of Harry Potter, then our spirits would not be so different, and we could exist in the same world.”