Harry Potter and the Methods of Rationality

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 our spy," Hermione said carefully.

The young Slytherin shrugged. "I think I did a good job of telling which ones really want to sell out Malfoy, I'm not sure anyone really wants to sell out Potter to you. But Nott is a sure bet for betraying Potter to Malfoy and since I had Entwhistle approach him supposedly on behalf of Malfoy and Entwhistle really reports to us, that's almost as good -"

Hermione closed her eyes for a moment. "We're going to lose, aren't we?"

"Look," Zabini said patiently, "You're in the lead right now on Quirrell points. We just have to not lose this last battle completely and you'll have enough Quirrell points to win the Christmas wish."

Professor Quirrell had announced that the final battle would operate on a formal scoring system, which he'd been asked to do to avoid recriminations afterward. Each time you shot someone, the general of your army got two Quirrell points. A gong would ring through the battle area (they didn't know yet where they would be fighting, though Hermione was hoping for the forest again, where Sunshine did well) and its pitch would tell which army had won the points. And if anyone was faking being hit, the gong would ring out anyway, and then a double gong would ring later, after no fixed time, to hail the retraction. And if you called the name of an army, cried "For Sunshine!" or "For Chaos!" or "For Dragon!", it switched your allegiance to that army...

Even Hermione had been able to see the flaw in that set of rules. But Professor Quirrell had gone on to announce that if you'd been originally assigned to Sunshine, nobody could shoot you in the name of Sunshine - or rather, they could, but then Sunshine lost a single Quirrell point, symbolized by a triple gong. That prevented you from shooting your own soldiers for points, and discouraged suiciding before the enemy got you, but you could still shoot spies if you had to.

Right now, Hermione had two hundred and forty-four Quirrell points, and Malfoy had two hundred and nineteen, and Harry had two hundred and twenty-one; and there were twenty-four soldiers in each army.

"So we fight carefully," Hermione said, "and just try not to lose too badly."

"No," said Zabini. The young Slytherin's face was now serious. "The problem is, Malfoy and Potter both know that their only way to win is to combine and crush us, then fight it out on their own. So here's what I think we