Harry Potter and the Methods of Rationality

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 prefer the rule of men, it's vastly more efficient... There's no constraining legal rules at all, then?'

Light glinted off the old wizard's half-moon glasses; he spoke carefully, and not without anger. 'Legally, Harry, we are dealing with a blood debt from Hermione Granger to the House of Malfoy. The Lord of Malfoy proposes a repayment of that debt, and then the Wizengamot votes on his proposal. That is all.'

'But...' Harry said slowly. 'Lucius was Sorted into Slytherin, he's got to realize that Hermione was just a pawn. Not the one he should actually be angry at. Right?'

'No, Harry Potter,' Albus Dumbledore said heavily. 'That is how you wish Lucius Malfoy would think. Lucius Malfoy himself... will not share your desire that he think that way.'

Harry gazed at the Headmaster, his eyes growing colder, at the same time that Minerva herself had to clamp down harder on her own emotions, stop her pacing and try to breathe. She'd been trying not to think about it, trying to turn her thoughts away from it, but she knew. She'd known since the instant she'd heard. She could see it in Albus's eyes -

'Is she facing capital punishment?' Harry said quietly, and chills went all the way down Minerva's spine at the undertones of that voice.

'No!' Albus said. 'No, not the Kiss, not Azkaban, not for a first-year in Hogwarts. Our country is not so lost, not yet.'

'But Lucius Malfoy,' Severus said tonelessly, 'certainly will not be satisfied with only snapping her wand.'

'All right,' Harry said commandingly. 'As I see it, we've got two essential lines of attack. Line one, find the real culprit. Line two, other leverage over Lucius. Professor Quirrell saved Draco's life, does that create a blood debt from House Malfoy to him that he could redeem to cancel Hermione's?'

Minerva blinked in startlement again.

'No,' Dumbledore said. The old wizard shook his head. 'It was a clever thought - but no, Harry, I'm afraid not. Even in the unlikely event that our Defense Professor reveals himself to be of a Noble House, there is an exception when the Wizengamot suspects that the life-debt may have been created deliberately, for that very purpose. And the Defense Professor is hardly above suspicion. Thus Lucius would argue.'

Harry nodded once, face set. 'So a commoner can have a blood debt to a Noble House, but not vice versa. Somehow I'm not surprised. But House Potter does count as a Noble House, from what I've heard. Headmaster, I know I said I wouldn't - but under the circumstances - that time Draco cast that torture hex on me, is that debt enough -'

'No,' the old wizard said (even as she blurted 'What?' and Severus lifted an eyebrow). 'It would not have been enough, and now it is no debt at all. You are an Occlumens and cannot testify under Veritaserum. Draco Malfoy could be Obliviated of his own memory before he could testify -' Albus hesitated. 'Harry... whatever you have done with Draco, you must assume that Lucius Malfoy will soon know of it.'

Harry's head sank into his hands. 'He'll give Draco Veritaserum.'

'Yes,' Albus said quietly.

The Boy-Who-Lived didn't say anything, as he sat with his head in his hands.

The Potions Master looked genuinely shocked. 'Draco really was trying to help Miss Granger,' Severus said. 'You - Potter, you actually -'

'Turned him?' Harry said from between his hands. 'I was about three-quarters done. Taught him the Patronus Charm and everything. I don't know what will happen now, though.'

'Voldemort has struck a grave blow against us, this day,' Albus said. The sound of old wizard's voice was like the look of the boy with his head in his hands. 'He has taken two of our pieces, with one... No. I should have seen it earlier. He has taken two of Harry's pieces with one move. Voldemort has begun his game again, not against myself, but against Harry. Voldemort knows the prophecy, he knows who his last foe shall be. He is not waiting to face Hermione Granger and Draco Malfoy at Harry's side when they are grown. He is striking at them now.'

'Maybe it's You-Know-Who and maybe it isn't,' Harry said, his voice sounding a little unsteady. 'Let's not narrow down the hypothesis space prematurely.' Harry took a breath and lowered his hands. 'The other thing we can try is to nail the real culprit before the trial - or at least find solid evidence that someone else did it.'

'Mr. Potter,' said Minerva, 'Professor Quirrell told the Aurors that he knew of someone with a motive to harm Mr. Malfoy. Do you know who he was talking about?'

'Yes,' Harry said, after a hesitation. 'But I think I shall conduct that part of my investigation with the Defense Professor - just as I would not have Professor Quirrell in the room while we were discussing how to investigate him.'

'He suspects me?' Severus said, then gave a short laugh. 'Why, of course he does.'

'My own plan,' said Harry, 'is to go look at the trophy room where the supposed duel took place and see if I can discover anything anomalous. If you can tell the investigating Aurors to let me through -'

'What investigating Aurors?' Severus said tonelessly.