Harry Potter and the Methods of Rationality

by Eliezer Yudkowsky

  "Tell me," the man said in a disinterested voice that didn't seem to quite fit the rough throat - Polyjuice, Bahry would have called it, if he'd thought that anyone could possibly do magic that delicate from inside someone else's body - "what did you do in the last war? Put yourself in harm's way, or stay out of trouble?"

  "Harm's way," said Bahry. His voice kept the iron calm of an Auror with nearly a hundred full years on the force, seven months short of mandatory retirement, Mad-Eye Moody couldn't have said it with any more hardness.

  "Fight any Death Eaters?"

  Now a grim smile graced Bahry's own face. "Two at once." Two of You-Know-Who's own warrior-assassins, personally trained by their dark master. Two Death Eaters at once against Bahry alone. It had been the toughest fight of Bahry's life, but he'd stood his ground, and walked away with only the loss of his left hand.

  "Did you kill them?" The man sounded idly curious, and he continued to draw threads of fire out of the much-diminished stunbolt still captive on the end of his wand, his fingers now weaving small patterns of Bahry's own magic before flicking to disperse them.

  Sweat broke out on Bahry's skin beneath his robes. His metal hand flashed downward, ripped the mirror from his belt - "Bahry to Mike, I need backup!"

  There was a pause, and silence.

  "Bahry to Mike!"

  The mirror lay dull and lifeless in his hand. Slowly, Bahry put it back on his belt.

  "It's been quite a while since I had a serious fight with a serious opponent," the man said, still not looking up at Bahry. "Try not to disappoint me too much. You can attack whenever you're ready. Or you can walk away with five hundred Galleons."

  There was a long silence.

  Then the air screamed like metal cutting glass as Bahry slashed his wand downward.

  Harry could hardly see it, could hardly make out anything amid the lights and flashes, his mirror's curve was perfect (they'd practiced that tactic before in the Chaos Legion) but the scene was still too small, and Harry had the feeling he wouldn't be able to understand even if he was watching from a meter away, it was all happening too fast, red blasts deflecting from blue shields, green bars of light clashing together, shadowy forms appearing and vanishing, he couldn't even tell who was casting what, except that the Auror was shouting incantation after incantation and frantically dodging while Professor Quirrell's Polyjuiced form stood in one place and flicked his wand, mostly silently, but now and then pronouncing words in unrecognizable languages that would white out the whole mirror and show half the Auror's shielding torn away as he staggered back.

  Harry had seen exhibition duels between the strongest seventh-year students, and this was so far above it that Harry's mind felt numbed, looking at how far he had left to go. There wasn't a single seventh-year student who could have lasted half a minute against the Auror, all three seventh-year armies put together might not be able to scratch the Defense Professor...

  The Auror had fallen to the ground, one knee and one hand supporting himself as the other hand gestured frantically and his mouth shouted desperate words, the few incantations that Harry recognized were all shield spells, as a flock of shadows spun around the Auror like a whirlwind of razors.

  And Harry saw Professor Quirrell's Polyjuiced form deliberately point his wand at where the Auror kneeled and fought the last moments of his battle.

  "Surrender," said the gravelly voice.

  The Auror spat something unspeakable.

  "In that case," said the voice, "Avada -"

  Time seemed to move very slowly, like there was time to hear the individual syllables, Ke, and Da, and Vra, time to watch the Auror starting to throw himself desperately aside; and even though it was all happening so slowly, somehow there wasn't time to do anything, no time for Harry to open his lips and scream NO, no time to move, maybe even not any time to think.

  Only time for one desperate wish that an innocent man should not die -

  And a blazing silver figure stood before the Auror.

  Stood there just a fraction of a second before the green light struck home.

  Bahry was twisting frantically aside, not knowing if he was going to make it -

  His eyes were focused on his opponent and his onrushing death, so Bahry only briefly saw the outline of the brilliant silhouette, the Patronus brighter than any he'd ever seen, saw it just barely long enough to recognize the impossible shape, before the green and the silver light collided and both lights vanished, both lights vanished, the Killing Curse had been blocked, and then Bahry's ears were pierced as he saw his terrible opponent screaming, screaming, screaming, clutching at his head and screaming, starting to fall as Bahry was already falling -

  Bahry hit the ground, falling from his own frantic lunge, and his dislocated left shoulder and broken rib screamed in protest. Bahry ignored the pain, managed to scramble back to his knees, brought up his wand to stun his opponent, he didn't understand what was happening but he knew that this was his only chance.

  "Stupefy!"

  The red bolt struck out toward the man's falling body, and was torn apart in midair and dissipated - and not by any shield. Bahry could see it, the wavering in the air that surrounded his fallen and screaming opponent.

  Bahry could feel it like a deadly pressure on his skin, the flux of magic building and building and building toward some terrible breaking point. His instincts screamed at him to run before the explosion came, this was no Charm, no Curse, this was wizardry run wild, but before Bahry could even finish getting to his feet -

  The man threw his wand away from himself (he threw away his wand!) and a second later, his form blurred and vanished entirely.

  A green snake lay motionless on the ground, unmoving even before Bahry's next stunner spell, fired in sheer reflex, hit it without resistance.

  As the dreadful flux and pressure began to dissipate, as the wild wizardry died back down, Bahry's dazed mind noticed that the scream was continuing. Only it sounded different, like the scream of a young boy, coming from the stairs leading down to the next lower level.

  That scream choked off too, and then there was silence except for Bahry's frantic panting.

  His thoughts were slow, confused, disarrayed. His opponent had been insanely powerful, that hadn't been a duel, it had been like his first year as a trainee Auror trying to fight Madam Tarma. The Death-Eaters hadn't been a tenth that good, Mad-Eye Moody wasn't that good... and who, what, how in the name of Merlin's balls had anyone blocked a Killing Curse?

  Bahry managed to summon the energy to press his wand against his rib, mutter the healing spell, and then press it again to his shoulder. It took more out of him than it should have, took far too much out of him, his magic was within a bare breath of utter exhaustion; he didn't have anything left for his minor cuts and bruises or even to reinforce the scraps left of his shielding. It was all he could do not to let his Patronus go out.

  Bahry breathed deeply, heavily, steadied his breath as much as he could before he spoke.

  "You," Bahry said. "Whoever you are. Come out."

  There was silence, and it occurred to Bahry that whoever it was might be unconscious. He didn't understand what had just happened, but he'd heard the scream...

  Well, there was one way to test that.

  "Come out," said Bahry, making his voice harder, "or I start using area-effect curses." He probably couldn't have managed one if he'd tried.

  "Wait," said a boy's voice, a young boy's voice, high and thin and wavering, like someone was holding back exhaustion or tears. The voice now seemed to be coming from closer to hand. "Please wait. I'm - coming out -"

  "Drop the invisibility," growled Bahry. He was too tired to bother with anti-Disillusionment Charms.

  A moment later, a young boy's face emerged from within an unfolding invisibility cloak, and Bahry saw the black hair, the green eyes, the glasses, and the angry red lightning-bolt scar.

  If he'd had twenty fewer years of experience under his belt he might have blinked. Instead he jus
t spat something that he probably shouldn't ought to say in front of the Boy-Who-Lived.

  "He, he," the boy's wavering voice said, his young face looked frightened and exhausted and tears were still trickling down his cheeks, "he kidnapped me, to make me cast my Patronus... he said he'd kill me if I didn't... only I couldn't let him just kill you..."

  Bahry's mind was still dazed, but things were slowly starting to click into place.

  Harry Potter, the only wizard ever to survive a Killing Curse. Bahry might have been able to dodge the green death, he'd certainly been trying, but if the matter came up before the Wizengamot, they'd rule it was a life debt to a Noble House.

  "I see," Bahry said in a much gentler growl. He started to walk toward the boy. "Son, I'm sorry for what you've been through, but I need you to drop the cloak and drop your wand."

  The rest of Harry Potter emerged from invisibility, showing the sweat-soaked blue-trimmed Hogwarts robes, and his right hand clutching an eleven-inch holly wand so hard his knuckles were white.

  "Your wand," Bahry repeated.

  "Sorry," whispered the eleven-year-old boy, "here," and he held out the wand toward Bahry.

  Bahry barely stopped himself from snarling at the traumatized boy who'd just saved his life. Instead he overrode the impulse with a sigh, and just stretched out a hand to take the wand. "Look, son, you're really not supposed to point a wand at -"

  The wand's end twisted lightly beneath Bahry's hand just as the boy whispered, "Somnium."

  Harry stared at the Auror's crumpled body, there was no sense of triumph, just a crushing sense of despair.

  (Even then it might not have been too late.)

  Harry turned to look at where the green snake lay motionless.

  "Teacher?" hissed Harry. "Friend? Pleasse, are you alive?" An awful fear was taking hold in Harry's heart; in that moment he had entirely forgotten that he'd just seen the Defense Professor try to kill a police officer.

  Harry pointed his wand at the snake, and his lips even began to shape the word Innervate, before his brain caught up with him and screamed at him.

  He didn't dare use magic on Professor Quirrell.

  Harry had felt it, the burning, tearing pain in his head, like his brain was about to split in half. He'd felt it, his magic and Professor Quirrell's magic, matched and anti-harmonized in a fulfillment of doom. That was the mysterious terrible thing that would happen if Harry and Professor Quirrell ever got too close to each other, or if they ever cast magic on each other, or if their spells ever touched, their magic would resonate out of control -

  Harry stared at the snake, he couldn't tell if it was breathing.

  (The last seconds ticked away.)

  He turned to stare at the Auror, who had seen the Boy-Who-Lived, who knew.

  The full magnitude of the disaster crushed in on Harry like a thousand hundred-ton weights, he'd managed to stun the Auror but now there was nothing left to do, no way to recover, the mission had failed, everything had failed, he had failed.

  Shocked, dismayed, despairing, he didn't think of it, didn't see the obvious, didn't remember where the hopeless feelings were coming from, didn't realize that he still needed to recast the True Patronus Charm.

  (And then it was already too late.)

  Auror Li and Auror McCusker had rearranged their chairs around the table, and so they both saw it at the same time, the naked, skeletally thin horror rising up to hover outside the window, the headache already hitting them from seeing it.

  They both heard the voice, like a long-dead corpse had spoken words and those words themselves had aged and died.

  The Dementor's speech hurt their ears as it said, "Bellatrix Black is out of her cell."

  There was a split second of horrified silence, and then Li tore out of his chair, heading for the communicator to call in reinforcements from the Ministry, even as McCusker grabbed his mirror and started frantically trying to raise the three Aurors who'd gone on patrol.

  Chapter 55: The Stanford Prison Experiment, Pt 5

  In a scarred and ruined corridor, lit by dim gas lights, a boy slowly crept forward, one hand stretched out, toward the unmoving snake that was the body of his teacher.

  Harry was only a meter away from the snake's body when he first felt it, tickling at the edge of his perception.

  Ever so weakly, a sense of doom...

  Professor Quirrell was alive, then.

  The thought engendered no feeling of joy, only a sort of empty despair.

  Harry would still be caught soon, and no matter how he tried to explain, it still wouldn't look good. No one would trust him again, they would think he was the next Dark Lord, they wouldn't help him when it came time to fight Lord Voldemort, Hermione would give up on him, probably even Dumbledore would look for another hero...

  ...maybe they'd just send him home to his parents.

  He had failed.

  Harry looked at the crumpled body of the police officer he'd stunned, the already-drying blood from the minor cuts and slashes, the burned places on the intricately embroidered red robes.

  He'd been stupid. He shouldn't have stunned the police officer, should have just stayed with his original story about being kidnapped by Professor Quirrell...

  It might not be too late, whispered a voice inside him. You might still be able to fix your mistake. The Auror saw you, he remembers that you stunned him... but if he were dead, if Professor Quirrell were dead, if Bellatrix were dead, there would be no one to contradict your story.

  Slowly, Harry's hand started to rise, pointing his wand at the police officer and -

  Harry's hand halted.

  He had a distant sense he was behaving uncharacteristically of himself, somehow. Like there was something he'd forgotten, something important, but he was having trouble remembering what it was, exactly.

  Oh. That was right. He was someone who believed in the value of human life.

  A sense of puzzlement accompanied the thought, he couldn't quite remember why other people's lives had seemed valuable...

  All right, said the logical part of him, why has my mind changed between then and now?

  Because he was in Azkaban...

  And he'd forgotten to recast the Patronus Charm...

  Doing anything at all, somehow, seemed like a tremendous effort, like the thought of action itself was a weight too heavy to lift; but it did seem like a good idea to recast the Patronus Charm, for he was still able to be afraid of Dementors. And though he couldn't remember what it was like to be happy, he knew that this wasn't it.

  Harry's hand rose to hold his wand level before him, his fingers took the starting positions.

  And then Harry paused.

  He couldn't... quite remember... what he'd used as his happy thought.

  That was odd, it had been something very important, he really ought to be able to remember it... something to do with death? But that wasn't happy...

  His body was shivering, Azkaban hadn't seemed so cold before, and it seemed to be getting colder even as he thought. It was too late for him, he'd already sunk too far, he'd never be able to cast the Patronus Charm now -

  That may be the Dementation talking rather than an accurate estimate, observed the logical part of himself, habits that had been encoded into sheer reflex, requiring no energy to activate. Think of the Dementors' fear as a cognitive bias, and try to overcome it the way you would overcome any other cognitive bias. Your hopeless feelings may not indicate that the situation is actually hopeless. It may only indicate that you are in the presence of Dementors. All negative emotions and pessimistic estimates must now be considered suspect, fallacious until proven valid.

  (If you'd been watching the boy as he thought, you would have seen a distant, abstract, puzzled frown move across his face, below the glasses and the lightning-bolt scar. His hand stayed in the starting position for the Patronus Charm, and did not move.)

  The presence of Dementors interferes with the part of you that processes happiness. If you cannot retr
ieve your happy thought by mnemonic association on the key of happiness, perhaps you can get at the memory some other way instead. When was the last time you talked to someone about the Patronus Charm?

  Harry couldn't seem to remember that either.

  A crushing wave of despair swept over him, and was dismissed by the logical part of himself as untrustworthy, external, not-Harry, the dull weight still pressed him down but his mind went on thinking, it didn't take much effort to think...

  When was the last time you talked to someone about Dementors?

  Professor Quirrell had said that he was already able to feel the presence of Dementors, and Harry had said to Professor Quirrell... he'd told Professor Quirrell...

  ...to hold to the memory of the stars, of falling bodilessly through space, like an Occlumency barrier across his entire mind.

  His second Defense class of the year, on Friday, that was when Professor Quirrell had shown him the stars, and again on Christmas.

  It didn't take much effort to remember them, the searing points of white against perfect blackness.

  Harry remembered the great cloudy wash of the Milky Way.

  Harry remembered the peace.

  Some of the coldness at the fringes of his limbs seemed to retreat.

  There were words he had spoken out loud on the day he'd first cast the Patronus Charm, his mind could remember the sounds and the speech even as the feelings seemed distant...

  ...I thought of my absolute rejection of death as the natural order.

  You cast the True Patronus Charm by thinking about the value of human life.

  ...But there are other lives that are still alive to be fought for. Your life, and my life, and Hermione Granger's life, all the lives of Earth, and all the lives beyond, to be defended and protected.

  Then the idea of killing everyone... that hadn't been his true self, that had been the Dementation talking...

  Despair was the Dementors' influence.

  Where there's life, there's hope. The Auror is still alive. Professor Quirrell is still alive. Bellatrix is still alive. I'm still alive. No one's actually died yet...