Harry Potter and the Methods of Rationality

"I do not know," the old wizard said slowly, "I know all too little, of the methods of Voldemort's immortality. He searched out those books before I did, I think. All I could find were ancient tales, scattered across too many volumes for him to remove. But to find truth among many stories is also a wizard's mastery, and this I have endeavored to do. There is a human sacrifice, a murder, of that I am certain; committed in coldest blood, the victim dying in horror. And old, old tales of wizards possessed, doing mad deeds, claiming the names of Dark Lords thought defeated; and there is usually a device, of that Dark Lord, which they wield..." Albus looked at Harry, the ancient eyes searching the younger. "I think, Harry - though you will call it only inference - that the act of murder splits the soul. That by ritual of blackest horror, the torn fragment of soul is chained to this world. To a material thing of this world. Which must be, or which then becomes, a device of power."

Horcrux. The terrible name echoed in Minerva's mind, though it seemed that - for what reason she did not know - Albus would not speak that word in front of Harry.

"And therefore," the old wizard finished quietly, "the remainder of the soul is bound to its chained part, lingering here when its body is destroyed. A sad and painful existence, I think it would be; less than spirit, less than the meanest ghost..." The old wizard's eyes were locked on Harry, who gazed back with his eyes narrowed. "It would take time for that mutilated soul to regain a mockery of life. That is why we have had our ten-year reprieve, I believe; why Voldemort did not return at once. But in time... that revenant would become capable of rising again." The old wizard spoke with grim precision. "It is clear, from the stories, that the Dark Lords who return by possessing another's form, wield lesser magics than they once knew. I do not think Voldemort would be satisfied with that. He would take some other avenue to life. But Voldemort was more Slytherin than Salazar, grasping at every opportunity. He would use his pitiful state, use his power of possession, if he had reason. If he could benefit by another's... inexplicable fury." Albus's voice had fallen to almost a whisper. "That is what I suspect happened to Miss Granger."

Minerva's throat was very dry. "He's here," she gasped. "Here, in Hogwarts -"

Then she stopped, because the reason Voldemort had come to Hogwarts -

The old wizard glanced at her only briefly, and said, still in that whisper, "I am sorry, Minerva, you were right."

Harry's voice was edged. "Right about what?"

"Voldemort's strongest avenue to life," Dumbledore said heavily. "The most desirable road for him, by which he would rise greater and more terrible than ever before. It is guarded here, within this castle -"

"Excuse me," Harry said politely. "Are you stupid?"

"Harry," she said, but there was no force in her voice.

"I mean, maybe you haven't noticed this, Headmaster Dumbledore, but this castle is full of CHILDREN -"

"I had no choice!" bellowed Dumbledore. The blue eyes were blazing now, beneath the half-moon spectacles. "I do not own it, that thing which Voldemort desires. It belongs to another, and is held here by his consent! I asked if it could be kept in the Department of Mysteries. But he would not permit that - he said it must be within the wards of Hogwarts, in the place of the Founders' protection -" Dumbledore passed his hand across his forehead. "No," the old wizard said in a quieter voice. "I cannot pass this blame to him. He is right. There is too much power in that thing, too much that men desire. I agreed that the trap should be laid behind the wards of Hogwarts, in the place of my own power." The old wizard bowed his head. "I knew Voldemort would worm his way here somehow, and planned to trap him. I did not think - I did not dream - that he would tarry in an enemy fortress one minute longer than he must."

"But," said Severus in some puzzlement, "what would the Dark Lord possibly gain by killing Lucius's only heir?"

"Point of order," Harry Potter said, a hard edge in his voice. "The motives of whoever's behind this are not the primary issue. Our top priority at this point is that an innocent Hogwarts student is in trouble! "

The green eyes locked with the blue, as Albus Dumbledore gazed back at the Boy-Who-Lived -

"Quite right, Mr. Potter," Minerva said, she hadn't even thought about it, the words just seemed to pop out of her lips. "Albus, who is watching over Miss Granger now?"

"Professor Flitwick has gone to her," the Headmaster said.

"She needs a lawyer," Harry said. "Anyone who just blurts out 'I did it' to the police -"

"Unfortunately," Minerva said, her tone taking on some of Professor McGonagall's sternness without thinking, "I doubt an attorney will be any use to Miss Granger at this point, Mr. Potter. She is to face the judgment of the Wizengamot, and they would be exceedingly unlikely to free her on a technicality."

Harry was looking at her with an utterly incredulous expression, as though suggesting that Hermione Granger didn't need an attorney was akin to suggesting that she be set on fire.

"She is correct, Mr. Potter," Severus said quietly. "Few court processes in this country involve solicitors."

Harry lifted his glasses and rubbed his eyes, briefly. "Fine. How do we get Hermione off the hook, exactly? I suppose it's too much to hope that with all the lawyers gone, the judges understand the concept of 'common sense' and 'prior probability' well enough to realize that twelve-year-old girls basically never commit cold-blooded murders?"

"It is the Wizengamot that she faces," said Severus. "The oldest Noble Houses, and certain other wizards of influence." Severus's face twisted in something approaching his customary sarcasm. "As for them showing common sense - you might as well expect them to make you a bacon sandwich, Potter."

Harry nodded, his mouth set. "Exactly what sort of penalty is Hermione facing? Snapped wand and expulsion -"

"No," Severus said. "Nothing that light. Are you willfully misunderstanding, Potter? She is facing the Wizengamot. There is no set penalty. There is only the vote."

Harry Potter murmured, "The rule of law, in complex times, has proved itself deficient; we much