Harry Potter and the Methods of Rationality

"Yes, I am." Professor Quirrell leaned back against the grey wood again, his eyes drifting up to the dense net of branches, the falling night scarcely visible between the complex crossings. "I simply wished to learn whether you would call me on it, since you are pretending to know so little." The Defense Professor smiled to himself.

The Potions Master looked like he was about to choke on his own fury. "What do you want? "

"Nothing, really," said the Defense Professor, continuing to gaze at the forest ceiling. "I was only curious. I suppose I shall just watch and see where your plotting goes, and meanwhile I will say nothing to the Headmaster - so long as you are willing to do me a favor now and then, of course." A dry smile crossed the face. "You are dismissed for now, Severus Snape. Though I wouldn't mind having another little chat soon, if you're willing to speak with me honestly of where your loyalties lie. And I do mean honestly, not the false faces you've shown today. You might find you have more allies than you thought. Take some time to think it over, my friend."

Aftermath: Draco Malfoy and -

A rainbow hemisphere, a dome of solid force with little chromaticity of its own which sent back the infringing light in splintered reflections, iridescent in many colors, as it fractured the shine of the many-splendored chandeliers of the Slytherin common room.

Sheltered beneath the rainbow hemisphere, the terrified face of a young witch who had never fought bullies, who had not joined any of Professor Quirrell's armies, who was getting Acceptable marks at best in her Defense class, who could not have cast a Prismatic Barrier even to save her own life.

"Oh, stop it," said Draco Malfoy, making his voice sound bored despite the sweat that had broken out underneath his robes, as he kept his wand pointed at the barrier that was sheltering Millicent Bulstrode.

He couldn't remember making the decision, there'd just been the two older boys about to hex Millicent, the common room silently staring, and then Draco's hand had just drawn his wand and cast the barrier, leaving his heart to pump itself full of shocked adrenaline while his poor sad brain frantically racked itself for explanations -

The two older boys were straightening up from where they'd been looming over Millicent, turning to Draco, looking at him with a mixture of shock and anger. Gregory and Vincent beside him had already drawn their own wands, but weren't pointing them. All three of them together couldn't have won, anyway.

But the older boys wouldn't hex him. Nobody could possibly be stupid enough to hex the next Lord Malfoy.

It wasn't fear of being hexed that was making Draco sweat beneath his robes, as he desperately hoped the beads of water weren't visible on his forehead.

Draco was sweating because of the dawning and sickening certainty that even if he got away with this now, if he kept down this path, there would come a time when it would all come crashing down; and then he might not be the next Lord Malfoy anymore.

"Mr. Malfoy," said the oldest-looking boy. "Why are you protecting her?"

"So you've located the mistress of the conspiracy," Draco said with a Number Two Sneer, "and it's, let me get this straight now, a first-year girl named Millicent Bulstrode. She's just a conduit, you niddlewit!"

"So?" demanded the older boy. "She still helped them!"

Draco lifted his wand and the Prismatic Sphere winked out. Still talking in a bored voice, Draco said, "Did you know what you were doing, Miss Bulstrode?"

"N-no," Millicent stammered from where she was still sitting at her desk.

"Did you know where the Slytherin messages you were passing on were going to?"

"No!" said Millicent.

"Thank you," Draco said. "All of you please leave her alone, she's just a pawn. Miss Bulstrode, you may consider the favor you did me in February to have been repaid." And Draco turned back to his Potions homework, hoping to Merlin and back again that Millicent didn't say anything incredibly stupid like 'What favor?' -

"Then why," a voice said clearly from across the room, "did those witches go where a note from Millicent told them to go?"

Sweating even more, Draco lifted his head again to look at where Randolph Lee had spoken. "What did the fake note say exactly?" said Draco. "Was it, 'I command you to go forth in the name of the Dark Lady Bulstrode' or 'Please meet me here, sincerely Millicent?'"

Randolph Lee opened his mouth, hesitated for a fractional second -

"I thought so," said Draco. "That wasn't a very good test, Mr. Lee, it - it can -" A frantic, nerve-racking moment while he figured out how to say it without using Harry-words like false positive. "It can get the witches to go there if any of them is just friends with Millicent."

As though the matter had been entirely settled, Draco looked down again at his Potions homework, ignoring (except for the feeling of sick dread in his stomach) the whispers from around the room.

It was only out of the corner of his eye that he caught Gregory staring at him.

Draco's eyes rested on his Astronomy homework, but he couldn't make his mind focus there. If you were trying not to think about things Harry Potter had said, pretty much the worst possible thing you could do was look at your textbook's pictures of the night sky, and try to remember what you weren't supposed to know about how the planets wandered. Astronomy, a noble and prestigious art, a sign of learning and knowledge; only Muggles possessed secret modern artifacts which could do it a million billion times better using methods that Harry had tried to explain and which Draco still couldn't begin to understand except that apparently it didn't even take magic to make things do Arithmancy.

Draco looked at the pictures of constellations, and wondered if it was like this in the other Houses, if people were always threatening each other in Ravenclaw.

Harry Potter had told him once that soldiers on a battlefield didn't really fight for their country. Patriotism might get them to the battlefield in the first place, but once they were there, they fought to protect each other, the friends they'd trained with who were right in front of them. And Harry had observed, and Draco had known that it was true, that you couldn't use loyalty to a leader to power a Patronus Charm, it wasn't quite the right kind of warm and happy thought. But thinking of protecting someone