Eliezer Yudkowsky - Harry Potter and the Methods of Rationality

Like a punch in the stomach, that was how it felt, and the sickness in Minerva's belly redoubled. Anyone who'd watched a Chaos Legion battle knew whose hand that showed...

Madam Bones's voice continued. "We brought in Arthur Weasley from Misuse of Muggle Artifacts - he knows more about Muggle artifacts than any wizard alive - and gave him the descriptions from the Aurors on the scene, and he cracked it. It was a Muggle artifact called a rocker, and they call it that because you'd have to be off your rocker to ride one. Just six years ago one of their rockers blew up, killed hundreds of Muggles in a flash and almost set fire to the Moon. Weasley says that rockers use a special kind of science called opposite reaction, so the plan is to develop a jinx which will prevent that science from working around Azkaban."

"Thank you, Amelia," Albus said gravely. "Is that everything?"

"I'll check if we have anything from six hours forward," said the voice of Madam Bones, "if so they wouldn't have told me, but I'll have them tell you. Do you have anything you want to tell me, Albus? Which of those two possibilities is it looking like?"

"Not yet, Amelia," Albus said, "but I may have word for you soon."

He straightened up from the fire, then, which faded back to ordinary yellow flames. Every minute of the old wizard's years, every natural second since his birth and every second which Time-Turning had added, all of that plus a few extra decades for stress, was visible on his lined face.

"Severus?" the old wizard said. "What was it actually?"

"A rocket," said the half-blood Potions Master, who had grown up in the Muggle town of Spinner's End. "One of the most impressive Muggle technologies."

"How likely is Harry to know such arts?" said Minerva.

Severus drawled, "Oh, a boy like Mr. Potter knows all about rockets; that, dear Minerva, is a certainty. You must remember that things are done differently in the Muggle world." Severus frowned. "But rockets are dangerous, and expensive..."

"Harry has stolen and hidden an unknown amount of money from his Gringotts vault, perhaps thousands of Galleons," said the Headmaster, and then, to their twin stares, "That was not in my plan, but I made the mistake of sending the Defense Professor to supervise Harry's withdrawal of five Galleons for Christmas presents..." The Headmaster shrugged. "Yes, I agree, sheer folly in retrospect, let us continue."

Minerva quietly thudded her head a few times against the headrest of her chair.

"Nonetheless, Headmaster," Severus said. "Just because the Death Eaters never used Muggle artifacts in the first war, that does not mean he is ignorant. Rockets fell on Britain as weapons, in the Muggle side of Grindelwald's war. If he spent the summers of those years in a Muggle orphanage, as you told us, Headmaster... then he, too, has heard of rockets. And if he has been listening to reports of Mr. Potter and his mock battles using Muggle artifacts, he would certainly learn his enemy's strengths and try to redouble them himself. That is just how he thinks; any power he sees he will try to take for his own."

The old wizard was standing stock still, utterly motionless, even the hairs of his beard frozen in place like solid wires; and the thought came to Minerva, as frightening as any thought she'd ever had, that Albus Dumbledore was rooted to the spot in horror.

"Severus," Albus Dumbledore said, and his voice almost cracked, "do you realize what you are saying? If Harry Potter and Voldemort fight their war with Muggle weapons there will be nothing left of the world but fire!"

" What? " said Minerva. She had heard of guns, of course, but they weren't that dangerous to an experienced witch -

Severus spoke as though she weren't in the room. "Then perhaps, Headmaster, he is sending a deliberate warning to Harry Potter of exactly that; saying that any attack with Muggle weapons will be met with retaliation in kind. Command Mr. Potter to cease his use of Muggle technology in his battles; that will show him the message is received... and not give him any more ideas." Severus frowned. "Though, come to think of it, Mr. Malfoy - and of course Miss Granger - well, on second thought a blanket prohibition on technology seems wiser -"

The old wizard pressed both his hands to his forehead, and from his lips came an unsteady voice, "I begin to hope that it is Harry behind this escape... oh, Merlin defend us all, what have I done, what have I done, what will become of the world?"

Severus shrugged. "From the rumors I have heard, Headmaster, Muggle weapons are only slightly worse than the more... recondite aspects of wizardry -"

" Worse? " gasped Minerva, and then shut her mouth as though by force.

"Worse than any peril left in these fading years," said Albus. "Not worse than that which erased Atlantis from Time."

Minerva stared at him, feeling the sweat break out all along her spine.

Severus continued, still addressing Albus. "All the Death Eaters save Bellatrix would have betrayed him, all his supporters turned against him, all the powers of the world converged to destroy him, if he had been reckless with any truly dangerous potency. Is this so different, then?"

Some motion, some color, had returned to the old wizard's face. "Perhaps not..."

"And in any case," Severus said with a slightly condescending smile, "Muggle weapons are not so easy to obtain, not for a thousand Galleons or a thousand thousand."

Doesn't Harry just Transfigure the devices he uses in his battles? thought Minerva, but before she could open her mouth to ask -

The fireplace erupted in green flames, then, and the face of Pius Thicknesse, Madam Bones's assistant, appeared therein. "Chief Warlock?" said Thicknesse. "I have a report for you, transmitted from -" Thicknesse's eyes flickered over Minerva and Severus, "six minutes ago."

"Six hours ahead, you mean," said Albus. "These two are meant to hear it; deliver your report."

"We know how it was done," said Thicknesse. "In Bellatrix Black's cell, hidden in one corner, was a potions vial; and testing the traces of remaining fluid shows that it was an Animagus potion."

There was a long pause.

"I see..." Albus said heavily.

"Pardon me?" said Minerva. She didn't.

Thicknesse's head turned toward her. "Animagi, Madam McGonagall, in their Animagus forms, are of less interest to Dementors. All prisoners are tested before their arrival at Azkaban; and if they are Animagi, their Animagus form is destroyed. But we had not considered that someone protected by a Patronus Charm while taking the potion and performing the meditation, might be able to become an Animagus after they went to Azkaban -"

"I understood," Severus said, having by now put on his customary sneer, "that the Animagus meditation required considerable time."

"Well, Mr. Snape," Thicknesse barked, "records show that Bellatrix Black was an Animagus before she was sentenced to Azkaban and her form destroyed; so maybe her second meditation didn't take as much time as her first!"

"I would not have thought it possible for any prisoner of Azkaban to do such a thing..." Albus said. "But Bellatrix Black was a most powerful sorceress before her incarceration, and she might have done it if any witch could. Can Azkaban be secured against this method?"

"Yes," said the confident head of Pius Thicknesse. "Our expert says that it is nigh-unimaginable that an Animagus meditation could be performed in less than three hours, regardless of experience. All visits to prisoners allowed to receive them will be limited to two hours henceforth, and the Dementors will inform us if any Patronus Charm is maintained in the prison areas for longer than that."