Harry Potter and the Methods of Rationality

The second battle had been deranged.

And the next one would be worse, unless the three of them together succeeded in their last desperate attempt to stop it.

'Professor Quirrell, this is insanity,' Draco said flatly. 'This isn't Slytherin any more, it's just...' Draco was at a loss for words. He waved his hands helplessly. 'You can't possibly do any real plots with all this stuff going on. Last battle, one of my soldiers faked his own suicide. We have Hufflepuffs trying to plot, and they think they can, but they can't. Things just happen at random now, it doesn't have anything to do with who's cleverest, or which army fights best, it's...' He couldn't even describe it.

'I agree with Mr. Malfoy,' said Granger in the tones of someone who hadn't ever expected to hear herself saying those words. 'Allowing traitors isn't working, Professor Quirrell.'

Draco had tried forbidding anyone in his army to plot except him, and that had just driven the plots underground, no one wanted to be left out when the soldiers in other armies got to plot. After miserably losing their last battle, he'd finally given in and revoked his decree; but by then his soldiers had already started setting their own personal plans in motion, without any sort of central coordination.

After being told all the plans, or what his soldiers claimed were their plans, Draco had tried to sketch a plot to win the final battle. It had required considerably more than three different things to go right, and Draco had used Incendio on the paper and Everto to vanish the ashes, because if Father had seen it he would have been disowned.

Professor Quirrell's eyelids were half-closed, his chin resting on his hands as he leaned forward onto his desk. 'And you, Mr. Potter?' said the Defense Professor. 'Are you likewise in agreement?'

'All we'd need to do is shoot Franz Ferdinand and we could start World War One,' said Harry. 'It's gone to complete chaos. I'm all for it.'

'Harry!' said Draco in utter shock.

He didn't even realize until a second later that he'd said it at exactly the same time, and in exactly the same tone of indignation, as Granger.

Granger shot him a startled glance, and Draco carefully kept his face neutral. Oops.

'That's right!' said Harry. 'I'm betraying you! Both of you! Again! Ha ha!'

Professor Quirrell was smiling thinly, though his eyes were still half-closed. 'And why is that, Mr. Potter?'

'Because I think I can cope with the chaos better than Miss Granger or Mr. Malfoy,' said the traitor. 'Our war is a zero-sum game, and it doesn't matter whether it's easy or hard in an absolute sense, only who does better or worse.'

Harry Potter was learning far too fast.

Professor Quirrell's eyes moved beneath their lids to regard Draco, and then Granger. 'In truth, Mr. Malfoy, Miss Granger, I simply could not live with myself if I shut down the grand debacle before its climax. One of your soldiers has even become a quadruple agent.'

'Quadruple?' said Granger. 'But there's only three sides in the war!'

'Yes,' said Professor Quirrell, 'you'd think that, wouldn't you. I am not sure that there has ever in history been a quadruple agent, or any army with such a high fraction of real and pretended traitors. We are exploring new realms, Miss Granger, and we cannot turn back now.'

Draco left the Defense Professor's office with his teeth gritting hard against each other, and Granger looking even more annoyed beside him.

'I can't believe you did that, Harry!' said Granger.

'Sorry,' Harry said, not sounding sorry at all, his lips curved up in a merry smile of evil. 'Remember, Hermione, it is just a game, and why should generals like us be the only ones who get to plot? And besides, what are the two of you going to do about it? Team up against me?'

Draco traded glances with Granger, knowing that his own face was as tight as hers. Harry had been relying, more and more openly and gloatingly, on Draco's refusal to make common cause with a mudblood girl; and Draco was beginning to get sick of having that used against him. If this kept up much longer he was going to ally with Granger just to crush Harry Potter, and see how much the son of a mudblood liked that.

The terrifying part was how fast the whole thing had spiraled out of control.

Hermione stared at the parchment Zabini had given her, feeling utterly and completely helpless.

There were names, and lines connecting the names to other names, and some of the lines were in different colors and...

'Tell me,' said General Granger, 'is there anyone in my army who isn't a spy?'

The two of them weren't in the office but in another, deserted classroom, and they were alone; because, Colonel Zabini had said, it was now nearly certain that at least one of the captains was a traitor. Probably Captain Goldstein, but Zabini didn't know for sure.

Her question had put an ironic smile on the young Slytherin's face. Blaise Zabini always seemed a little disdainful of her, but he didn't seem to actively dislike her; nothing like the derision he held for Draco Malfoy, or the resentment he had developed for Harry Potter. She had worried at first about Zabini betraying her, but the boy seemed desperate to show that the other two generals were no better than him; and Hermione thought that while Zabini would probably be happy to sell her out to anyone else, he'd never let Malfoy or Harry win.

'Most of your soldiers are still loyal to you, I'm pretty sure,' said Zabini. 'It's just that no one wants to be left out of the fun.' The scornful look on the Slytherin's face made it clear what he thought of people who didn't take plotting seriously. 'So they think they can be double agents and secretly work for our side while pretending to betray us.'

'And that would also go for anyone in the other armies who says they want to be