Harry Potter and the Methods of Rationality

"It is my own wish also," Harry said.

"So that's how it is to be..." the old wizard said slowly. Something strange passed across his face. "Harry... you must realize that if you choose this man as your teacher and your friend, your first mentor, then one way or another you will lose him, and the manner in which you lose him may or may not allow you to ever get him back."

That hadn't occurred to Harry. But there was that jinx on the Defense position... one which had apparently worked with perfect regularity for decades...

"Probably," said Professor Quirrell quietly, "but he will have the full use of me while I last."

Dumbledore sighed. "I suppose it is economical, at least, since as the Defense Professor you're already doomed in some unknown fashion."

Harry had to work hard to suppress his expression as he realized what Dumbledore had actually been implying.

"I will inform Madam Pince that Mr. Potter is allowed to obtain books on Occlumency," said Dumbledore.

"There is preliminary training which you must do on your own," said Professor Quirrell to Harry. "And I do suggest that you hurry up on it."

Harry nodded.

"I'll take my leave of you then," said Dumbledore. He nodded to both Harry and Professor Quirrell, and departed, walking a bit slowly.

"Can you cast the spell again?" Harry said the moment Dumbledore was gone.

"Not today," said Professor Quirrell quietly, "and not tomorrow either, I'm afraid. It takes a lot out of me to cast, though less to keep going, and so I usually prefer to maintain it as long as possible. This time I cast it on impulse. Had I thought, and realized we might be interrupted -"

Dumbledore was now Harry's least favorite person in the entire world.

They both sighed.

"Even if I only ever see it once," Harry said, "I will never stop being grateful to you."

Professor Quirrell nodded.

"Have you heard of the Pioneer program?" Harry said. "They were probes that would fly by different planets and take pictures. Two of the probes would end up on trajectories that took them out of the Solar System and into interstellar space. So they put a golden plaque on the probes, with a picture of a man, and a woman, and showing where to find our Sun in the galaxy."

Professor Quirrell was silent for a moment, then smiled. "Tell me, Mr. Potter, can you guess what thought went through my mind when I finished assembling the thirty-seven items on the list of things I would never do as a Dark Lord? Put yourself in my shoes - imagine yourself in my place - and guess."

Harry imagined himself looking over a list of thirty-seven things not to do once he became a Dark Lord.

"You decided that if you had to follow the whole list all the time, there wouldn't be much point in becoming a Dark Lord in the first place," Harry said.

"Precisely," said Professor Quirrell. He was grinning. "So I am going to violate rule two - which was simply 'don't brag' - and tell you about something I have done. I don't see how the knowledge could do any harm. And I strongly suspect you would have figured it out anyway, once we knew each other well enough. Nonetheless... I shall have your oath never to speak of what I am about to tell."

"You have it!" Harry had a feeling this was going to be really good.

"I subscribe to a Muggle bulletin which keeps me informed of progress on space travel. I didn't hear about Pioneer 10 until they reported its launch. But when I discovered that Pioneer 11 would also be leaving the Solar System forever," Professor Quirrell said, his grin the widest that Harry had yet seen from him, "I snuck into NASA, I did, and I cast a lovely little spell on that lovely golden plaque which will make it last a lot longer than it otherwise would."

...

...

...

"Yes," Professor Quirrell said, who now seemed to be standing around fifty feet taller, "I thought that was how you might react."

...

...

...

"Mr. Potter?"

"...I can't think of anything to say."

"'You win' seems appropriate," said Professor Quirrell.

"You win," Harry said immediately.

"See?" said Professor Quirrell. "We can only imagine what giant heap of trouble you would have gotten into if you had been unable to say that."

They both laughed.

A further thought occurred to Harry. "You didn't add any extra information to the plaque, did you?"

"Extra information?" said Professor Quirrell, sounding as if the idea had never occurred to him before and he was quite intrigued.

Which made Harry rather suspicious, considering that it'd taken less than a minute for Harry to think of it.

"Maybe you included a holographic message like in Star Wars?" said Harry. "Or... hm. A portrait seems to store a whole human brain's worth of information... you couldn't have added any extra mass to the probe, but maybe you could've turned an existing part into a portrait of yourself? Or you found a volunteer dying of a terminal illness, snuck them into NASA, and cast a spell to make sure their ghost ended up in the plaque -"