Harry Potter and the Methods of Rationality

Potter's abilities as a fighter. But after I heard rumors of one Ravenclaw facing down five older Slytherins, I interviewed several eyewitnesses and came to the conclusion that Harry Potter would be my most dangerous student."

A jolt of adrenaline poured into Harry's system, making him stand up straighter. He didn't know what conclusion Professor Quirrell had come to, but that couldn't be good.

"Ah, Professor Quirrell -" Harry started to say.

Professor Quirrell looked amused. "You're thinking that I've come up with a wrong answer, aren't you, Mr. Potter? You will learn to expect better of me." Professor Quirrell straightened from where he had leaned on the desk. "Mr. Potter, all things have their accustomed uses. Give me ten unaccustomed uses of objects in this room for combat!"

For a moment Harry was rendered speechless by the sheer, raw shock of having been understood.

And then the ideas started to pour out.

"There are desks which are heavy enough to be fatal if dropped from a great height. There are chairs with metal legs that could impale someone if driven hard enough. The air in this classroom would be deadly by its absence, since people die in vacuum, and it can serve as a carrier for poison gases."

Harry had to stop briefly for breath, and into that pause Professor Quirrell said:

"That's three. You need ten. The rest of the class thinks that you've already used up the whole contents of the classroom."

"Ha! The floor can be removed to create a spike pit to fall into, the ceiling can be collapsed on someone, the walls can serve as raw material for Transfiguration into any number of deadly things - knives, say."

"That's six. But surely you're scraping the bottom of the barrel now?"

"I haven't even started! Just look at all the people! Having a Gryffindor attack the enemy is an ordinary use, of course -"

"I will not count that one."

"- but their blood can also be used to drown someone. Ravenclaws are known for their brains, but their internal organs could be sold on the black market for enough money to hire an assassin. Slytherins aren't just useful as assassins, they can also be thrown at sufficient velocity to crush an enemy. And Hufflepuffs, in addition to being hard workers, also contain bones that can be removed, sharpened, and used to stab someone."

By now the rest of the class was staring at Harry in some horror. Even the Slytherins looked shocked.

"That's ten, though I'm being generous in counting the Ravenclaw one. Now, for extra credit, one Quirrell point for each use of objects in this room which you have not yet named." Professor Quirrell favored Harry with a companionable smile. "The rest of your class thinks you are in trouble now, since you've named everything except the targets and you have no idea what may be done with those."

"Bah! I've named all the people, but not my robes, which can be used to suffocate an enemy if wrapped around their head enough times, or Hermione Granger's robes, which can be torn into strips and tied into a rope and used to hang someone, or Draco Malfoy's robes, which can be used to start a fire -"

"Three points," said Professor Quirrell, "no more clothing now."

"My wand can be pushed into an enemy's brain through their eye socket" and someone made a horrified, strangling sound.

"Four points, no more wands."

"My wristwatch could suffocate someone if jammed down their throat -"

"Five points, and enough."

"Hmph," Harry said. "Ten Quirrell points to one House point, right? You should have let me keep going until I'd won the House Cup, I haven't even started yet on the unaccustomed uses of everything I've got in my pockets" or the mokeskin pouch itself and he couldn't talk about the Time-Turner or the invisibility cloak but there had to be something he could say about those red spheres...

"Enough, Mr. Potter. Well, do you all think you understand what makes Mr. Potter the most dangerous student in the classroom?"

There was a low murmur of assent.

"Say it out loud, please. Terry Boot, what makes your dorm-mate dangerous?"

"Ah... um... he's creative?"

"Wrong!" bellowed Professor Quirrell, and his fist came down sharply on his desk with an amplified sound that made everyone jump. "All of Mr. Potter's ideas were worse than useless!"

Harry started in surprise.

"Remove the floor to create a spike trap? Ridiculous! In combat you do not have that sort of preparation time and if you did there would be a hundred better uses! Transfigure material from the walls? Mr. Potter cannot perform Transfiguration! Mr. Potter had exactly one idea which he could use immediately, right now, without extensive preparation or a cooperative enemy or magic he does not know. That idea was to jam his wand through his enemy's eye socket. Which would be more likely to break his wand than kill his opponent! In short, Mr. Potter, I'm afraid that your proposals were uniformly awful."

"What?" Harry said indignantly. "You asked for unusual ideas, not practical ones! I was thinking outside the box! How would you use something in this classroom to kill someone?"

Professor Quirrell's expression was disapproving, but there were smile crinkles around his eyes. "Mr. Potter, I never said you were to kill. There is a time and a place for taking your enemy alive, and inside a Hogwarts classroom is usually one of those places. But to answer your question, hit them on the neck with the edge of a chair."