Harry Potter and the Methods of Rationality

Dumbledore got up again and began heading towards the podium. Apparently they were about to be treated to a speech -

And Harry was struck by the inspiration for a brilliant experimental test.

Hermione had said that Dumbledore was the most powerful wizard alive, right?

Harry reached into his pouch and whispered, "Comed-Tea".

For the Comed-Tea to work, it would have to make Dumbledore say something so ridiculous during his speech that even in Harry's state of mental preparedness, he would still choke. Like, all the Hogwarts students had to not wear any clothes for the whole school year, or everyone was going to be transformed into cats.

But then if anyone in the world could resist the power of the Comed-Tea, it would be Dumbledore. So if this worked, the Comed-Tea was literally invincible.

Harry pulled the ring on the Comed-Tea under the table, wanting to do this a bit unobtrusively. The can made a quiet hissing noise. A few heads turned to look at him, but soon turned back as -

"Welcome! Welcome to a new year at Hogwarts!" said Dumbledore, beaming at the students with his arms opened wide, as if nothing could have pleased him more than to see them all there.

Harry took a first mouthful of Comed-Tea and lowered the can again. He would swallow the pop a little at a time and try not to choke no matter what Dumbledore said -

"Before we begin our banquet, I would like to say a few words. And here they are: Happy happy boom boom swamp swamp swamp! Thank you!"

Everyone clapped and cheered, and Dumbledore sat down again.

Harry sat frozen as pop trickled out of the corners of his mouth. He had, at least, managed to choke quietly.

He really really really shouldn't have done that. Amazing how much more obvious that became one second after it was too late.

In retrospect he probably should have noticed something wrong when he was thinking about everyone being turned into cats... or even before then, remembered his mental note not to mess with Dumbledore... or his newfound resolution to be more considerate of others... or maybe if he'd had one single scrap of common sense...

It was hopeless. He was corrupt to the core. Hail the Dark Lord Harry. You couldn't fight fate.

Someone was asking Harry if he was all right. (Others were starting to serve themselves food, which had magically appeared on the table, whatever.)

"I'm all right," Harry said. "Excuse me. Um. Was that a... normal speech for the Headmaster? You all... didn't seem... very surprised..."

"Oh, Dumbledore's insane, of course," said an older-looking Ravenclaw sitting next to him who had introduced himself with some name Harry didn't even begin to remember. "Lots of fun, incredibly powerful wizard, but completely bonkers." He paused. "At some later point I'd also like to ask why green fluid came out of your lips and then disappeared, though I expect you promised the Sorting Hat not to talk about that either."

With a great effort, Harry stopped himself from glancing down at the incriminating can of Comed-Tea in his hand.

After all, the Comed-Tea hadn't just arbitrarily materialised a Quibbler headline about him and Draco. Draco had explained it in a way that made it seem like it had all happened... naturally? As if it had altered history to fit?

Harry was mentally imagining himself banging his forehead against the table. Wham, wham, wham went his head within his mind.

Another student lowered her voice to a whisper. "I hear that Dumbledore is secretly a genius mastermind controlling lots of stuff and he uses the insanity as a cover so that no one will suspect him."

"I've heard that too," whispered a third student, and there were furtive nods from around the table.

This couldn't help but catch Harry's attention.

"I see," whispered Harry, lowering his own voice. "So everyone knows that Dumbledore is secretly a mastermind."

Most of the students nodded. One or two looked suddenly thoughtful, including the older student sitting next to Harry.

Are you sure this is the Ravenclaw table? Harry managed not to ask out loud.

"Brilliant!" Harry whispered. "If everyone knows, no one will suspect it's a secret!"

"Exactly," whispered a student, and then he frowned. "Wait, that doesn't sound quite right -"

Note to self: The 75th percentile of Hogwarts students a.k.a. Ravenclaw House is not the world's most exclusive program for gifted children.

But at least he'd learned an important fact today. The Comed-Tea was omnipotent. And that meant...

Harry blinked in surprise as his mind finally made the obvious connection.

...that meant that as soon as he learned a spell to temporarily alter his own sense of humor, he could make anything happen, by making it so that he would only find that one thing surprising enough to do a spit-take, and then drinking a can of Comed-Tea.

Well that was a short little journey to godhood. Even I expected this to take longer than my first