Eliezer Yudkowsky - Harry Potter and the Methods of Rationality

" What? " Draco said.

"Draco has testified under Veritaserum that he tried to help Hermione Granger. I bet there'd be a lot of people in the opposition who'd take a chance on him rather than fight. I'm not sure how exactly you'd enforce it - Unbreakable Vows or Gringotts contracts or what - but there'll be some sort of enforceable compact about power going to Draco after he graduates Hogwarts. I'll throw any support the Boy-Who-Lived has behind that bargain. Try to persuade Longbottom and Bones and so on. Our first plan paves the way for that later, if you're careful to act honorable when you deal with Longbottom and Bones this time around."

"Father, I swear I didn't -"

Lucius's face twisted into a grim smile. "I know you didn't, son. Well." The white-haired man stared across the mighty golden table at Harry Potter. "Those terms are acceptable to me. But fail in any part of our agreement, whether our first bargain, or the second, and there shall be consequences for you, Harry Potter. Clever words will not halt that."

And Lucius Malfoy signed the parchment.

Mad-Eye Moody had been staring at the bronze door of the Gringotts meeting room for what seemed like hours, insofar as a man could stare at any one thing when his gaze always saw in all directions.

The trouble with trying to be suspicious of a man like Lucius Malfoy, Moody thought, was that you could spend an entire day thinking of everything he might be up to, and still not have finished.

The door cracked open and Harry Potter trudged out, small beads of sweat still on his forehead.

"Did you sign anything?" Mad-Eye demanded upon the instant.

Harry Potter looked at him silently, then reached into his robes and drew out a folded parchment. "The goblins are already executing this," said Harry Potter. "They made three copies before I left."

"MERLIN DAMN IT SON -" Moody paused as his Eye caught sight of the second half of the document as Harry Potter slowly, as though reluctantly, began to unfold the top upward. A glance sufficed to take in the paragraphs drawn in careful handwriting, Lucius Malfoy's elegant signature below Harry Potter's. And then Moody exploded, even as the top half of the document also began to enter his Sight. "You exonerate House Malfoy of any involvement in Hermione Granger's death? Do you have any idea what you've done, you little fool? Why in Merlin's name would you do something like WHAT -"

Sunday, April 19th, 6:34pm.

Daphne Greengrass walked quietly toward the Greengrass room below the Slytherin dungeons, the privilege of an Ancient House; on her way to drop off her trunk from the Hogwarts Express, before she joined the other students for dinner. The whole private area had been hers alone ever since Malfoy had gone. Her hand, held behind her, made repeated come-along gestures at her huge emerald-studded trunk, which seemed hesitant to follow. Maybe the enchantments on the sturdy old family device needed to be reapplied; or maybe her trunk was reluctant to follow her into Hogwarts, which was no longer safe.

There'd been a long talk between Mother and Father, after they'd been told about Hermione; with Daphne hiding around a doorway to listen, choking back her tears and trying not to make sounds.

Mother had said that the sad fact was that if only one student died every year, well, that still made Hogwarts safer than Beauxbatons, let alone Durmstrang. There were more ways for a young witch to die than being murdered. Beauxbatons's Transfiguration Master just wasn't on the same level as McGonagall, Mother had said.

Father had soberly remarked how important it was for the Greengrass heir to stay at Hogwarts where all the other Noble families sent their children to school (it was the reason for the old tradition of the Noble families synchronizing the birth of their heirs, to put them in the same year of Hogwarts, if they could). And Father had said that being heiress to a Most Ancient House meant you couldn't always stay away from trouble.

She could have done without hearing that last part.

Daphne gulped hard, as she turned the doorknob, and opened the door.

"Miss Greengrass -" whispered a shadowy, silvery-robed figure.

Daphne screamed and slammed the door and drew her wand and turned to run.

"Wait!" cried the voice, now higher and louder.

Daphne paused. That couldn't possibly be who it had sounded like.

Slowly, Daphne turned, and opened the door again.

"You!" Daphne said in astonishment, as she saw the face beneath the hood. "I thought you were -"

"I come back to you now," the silvery-robed figure said in a strong voice, "at the turn of the -"

" What are you doing in my bedroom? " shrieked Daphne.

"I heard you can cast the mist form of the Patronus Charm. Can I see?"

Daphne stared, and then her blood began to burn. "Why?" she said, keeping her wand level. "So you can kill everyone in Slytherin who casts un-Slytherin spells? We all know who it was had Hermione killed!"

The figure's voice rose. "I testified under Veritaserum that I tried to help Miss Granger! I really was trying to help her, when I grabbed her hand on the roof, when I helped her off the floor -"

Daphne kept her wand level. "Like your father couldn't tamper with the Aurors' record, if he wanted to! I wasn't born yesterday, Mister Malfoy! "

Slowly, as if not to cause alarm, the silver-robed figure drew a wand from his robes. Daphne's hand tightened on her own wand, but then she recognized the position of the fingers on the wand, the stance the figure was assuming, and she drew a shocked breath -

"Expecto Patronum! "

Silver light leapt from the end of the other's wand - and condensed, forming a shining serpent that seemed to coil in the air as though nesting there.

She just gaped.

"I did try to help Hermione Granger," Draco Malfoy said with a level voice. "Because I know the sickness at the heart of Slytherin's House, the reason why so many of us can't cast the Patronus Charm any more, is hate. Hate of Muggleborns, or just anyone really. People think that's all Slytherin is about now, not cunning or ambition or honorable nobility. And I even know, because it's obvious if you just look, that Hermione Granger wasn't weak at magic."

Daphne's mind had gone completely blank. Her eyes darted around nervously, just to check that there wasn't blood coming from under the doors, like the last time Something had Broken.

"And I've also figured out," Draco Malfoy said quietly, as the silver snake went on shining with unmistakeable light and warmth, "that Hermione Granger never really tried to kill me. Maybe she was False-Memory-Charmed, maybe she was Legilimized, but now that she's been murdered, it's obvious that Miss Granger was the target in the first place, when somebody tried to set her up for murdering me -"

"D-do-do you know what you're saying? " Daphne's voice broke. If Lucius Malfoy heard his heir saying that - he'd skin Draco and turn him into trousers!

Draco Malfoy smiled, metallic robes gleaming in the light of his full corporeal Patronus; it was a smile both arrogant and dangerous, like being turned into a pair of leather pants was beneath his concerns. "Yes," said Draco, "but it doesn't matter now. House Malfoy is returning House Potter's money and cancelling the debt."

Daphne walked over to her bed and then fell on it, hoping she could wake up from the dream once she was in bed.

"I'd like you to join a conspiracy," said the figure in the shining robes. "Everyone in Slytherin who can cast the Patronus Charm, and everyone who can learn. That's how we'll know to trust each other, when the Silvery Slytherins meet." With a dramatic gesture, Draco Malfoy cast back his hood. "But it won't work without you, Daphne Greengrass. You and your family. Your mother will negotiate it with Father, but I'd like the Greengrasses to hear the proposal from you, first." Draco Malfoy's voice lowered grimly. "There is much we must speak of, before we eat dinner."