Harry Potter and the Methods of Rationality

"You are a very foolish boy," Severus said. He wasn't smiling at all, now. "You have nothing that Lucius values more than my friendship. And if you did, I have other allies." His voice grew hard. "And I find it increasingly unlikely that you were not Sorted into Slytherin. How was it that you managed to stay out of my House? Ah, yes, because the Sorting Hat claimed it was joking. For the first time in recorded history. What were you really chatting about with the Sorting Hat, Potter? Did you have something that it wanted?"

Harry stared into Severus's cold gaze and remembered that the Sorting Hat had warned him not to meet anyone's eyes while thinking about - Harry dropped his gaze to Severus's desk.

"You seem oddly reluctant to look me in the eyes, Potter!"

A shock of sudden understanding - "So it was you the Sorting Hat was warning me about!"

"What?" said Severus's voice, sounding genuinely surprised, though of course Harry didn't look at his face.

Harry got up out of his desk.

"Sit down, Potter," said an angry voice from somewhere he wasn't looking.

Harry ignored it, and looked around the classroom. "I have no intention of letting one unprofessional teacher ruin my time at Hogwarts," Harry said with deadly calm. "I think I'll take my leave of this class, and either hire a tutor to teach me Potions while I'm here, or if the Board is really that locked up, learn over the summer. If any of you decide that you don't care to be bullied by this man, my sessions will be open to you."

"Sit down, Potter!"

Harry strode across the room and grasped the doorknob.

It didn't turn.

Harry slowly turned around, and caught a glimpse of Severus smiling nastily before he remembered to look away.

"Open this door."

"No," said Severus.

"You are making me feel threatened," said a voice so icy it didn't sound like Harry's at all, "and that is a mistake."

Severus's voice laughed. "What do you intend to do about it, little boy?"

Harry took six long strides forward away from the door, until he was standing near the back row of desks.

Then Harry drew himself upright and raised his right hand in one terrible motion, fingers poised to snap.

Neville screamed and dived under his desk. Other children shrank back or instinctively raised their arms to shield themselves.

"Harry don't!" shrieked Hermione. "Whatever you were going to do to him, don't do it!"

"Have you all gone mad?" barked Severus's voice.

Slowly, Harry lowered his hand. "I wasn't going to hurt him, Hermione," Harry said, his voice a little lower. "I was just going to blow up the door."

Though now that Harry remembered it, you weren't supposed to Transfigure things that were to be burned, which meant that going back in time afterward and getting Fred or George to Transfigure some carefully measured amount of explosives might not actually have been such a good idea...

"Silencio," said Severus's voice.

Harry tried to say "What?" and found that no sound was coming out.

"This has become ridiculous. I think you've been allowed to get yourself in enough trouble for one day, Potter. You are the most disruptive and unruly student I have ever seen, and I don't recall how many points Ravenclaw has right now, but I'm sure I can manage to wipe them all out. Ten points from Ravenclaw. Ten points from Ravenclaw. Ten points from Ravenclaw! Fifty points from Ravenclaw! Now sit down and watch the rest of the class take their lesson!"

Harry put his hand into his pouch and tried to say 'marker' but of course no words came out. For one brief moment that stopped him; and then it occurred to Harry to spell out M-A-R-K-E-R using finger motions, which worked. P-A-D and he had a pad of paper. Harry strode over to an empty desk, not the one he'd originally sat down in, and scrawled a brief message. He tore off that sheet of paper, put away the marker and pad in a pocket of his robes for quicker access, and held up his message, not to Snape, but to the rest of the class.

I'M LEAVING

DOES ANYONE ELSE

NEED TO GET OUT?

"You're insane, Potter," Severus said with cold contempt.

Aside from that, no one spoke.

Harry swept an ironic bow to the teacher's desk, walked over to the wall, and with one smooth motion yanked open a closet door, stepped in, and slammed the door shut behind him.

There was the muffled sound of someone snapping his fingers, and then nothing.

In the classroom, students looked at each other in puzzlement and fear.

The Potions Master's face was now completely enraged. He crossed the room in terrible strides and yanked open the closet door.

The closet was empty.

One hour earlier, Harry listened from inside the closed closet. There was no sound from outside, and no point in taking risks either.