Harry Potter and the Methods of Rationality

them to ensure they are drunk at the right time. This is the last of my supply, but I do not think there will ever come a finer occasion. Shall we?"

Dumbledore took a soda can from Harry, and Harry tossed another to Professor Quirrell. The two older men each muttered identical charms over the can and frowned briefly at the result. Harry, for his part, simply popped the top and drank.

The Defense Professor and the Headmaster of Hogwarts politely followed suit.

Harry said, "I thought of my absolute rejection of death as the natural order."

It might not be the right kind of warm feeling you needed to cast a Patronus Charm, but it was going into Harry's Top 10 nonetheless.

The looks he got from the Defense Professor and the Headmaster briefly made Harry nervous, as the spilled Comed-Tea faded out of existence; but then the two of them each glanced at the other and both apparently decided that they couldn't get away with doing anything really awful to Harry in the other's presence.

"Mr. Potter," said Professor Quirrell, "even I know that is not how things are supposed to work."

"Indeed," said Dumbledore. "Explain."

Harry opened his mouth, and then, as realization hit him, rapidly snapped his mouth shut again. Godric hadn't told anyone, nor had Rowena if she'd known; there might have been any number of wizards who'd figured it out and kept their mouths shut. You couldn't forget if you knew that was what you were trying to do; once you realized how it worked, the animal form of the Patronus Charm would never work for you again - and most wizards didn't have the right upbringing to turn on Dementors and destroy them -

"Erm, sorry about this," said Harry. "But I've just this instant realized that explaining would be an incredibly bad idea until you work some things out on your own."

"Is that the truth, Harry?" Dumbledore said slowly. "Or are you just pretending to be wise -"

"Headmaster!" said Professor Quirrell, sounding genuinely shocked. "Mr. Potter has told you that this spell is not spoken of with those who cannot cast it! You do not press a wizard on such matters!"

"If I told you -" Harry began.

"No," Professor Quirrell said, sounding rather severe. "You don't tell us why, Mr. Potter, you simply tell us that we are not to know. If you wish to devise a hint, you do so carefully, at leisure, not in the midst of conversation."

Harry nodded.

"But," said the Headmaster. "But, but what am I to tell the Ministry? You can't just lose a Dementor!"

"Tell them I ate it," said Professor Quirrell, causing Harry to choke on the soda he had unthinkingly raised to his lips. "I don't mind. Shall we head on back, Mr. Potter?"

The two of them began to walk the dirt path back to Hogwarts, leaving behind Albus Dumbledore staring forlornly at the empty cage and the three sleeping Aurors awaiting their Memory Charms.

Aftermath, Harry Potter and Professor Quirrell:

They walked for a while before Professor Quirrell spoke, and all background noise dropped into silence when he did.

"You are exceptionally good at killing things, my student," said Professor Quirrell.

"Thank you," Harry said sincerely.

"I am not prying," said Professor Quirrell, "but on the off-chance that it was only the Headmaster who you did not trust with the secret...?"

Harry considered this. Professor Quirrell already couldn't cast the animal Patronus Charm.

But you couldn't untell a secret, and Harry was a fast enough learner to realize that he ought to at least think for a while before unleashing this one upon the world.

Harry shook his head, and Professor Quirrell nodded acceptance.

"Out of curiosity, Professor Quirrell," said Harry, "if your bringing the Dementor to Hogwarts had been part of an evil plot, what would have been its goal?"

"Assassinate Dumbledore while he was weakened," Professor Quirrell said without even hesitating. "Hm. The Headmaster told you he was suspicious of me?"

Harry said nothing for a second while he tried to think of a reply, and then gave up when he realized he'd already answered.

"Interesting..." Professor Quirrell said. "Mr. Potter, it is not out of the question that there was a plot at work today. Your wand ending up that close to the Dementor's cage could have been an accident. Or one of the Aurors could have been Imperiused, Confunded, or Legilimized to exert an influence. Flitwick and myself should not be excluded as suspects, in your calculation. One notes that Professor Snape canceled all his classes today, and I suspect he is powerful enough to Disillusion himself; the Aurors cast detection charms early on, but they did not repeat them immediately before your turn. But most easily of all, Mr. Potter, the deed could have been plotted by Dumbledore himself; and if he did, why, he might also take steps in advance to cast your suspicion elsewhere."

They walked on for a few steps.

"But why would he?" Harry said.

The Defense Professor stayed quiet a moment, and then said, "Mr. Potter, what steps have you taken to investigate the Headmaster's character?"