Harry Potter and the Methods of Rationality

The night-lit torches of Hogwarts were far below. The platform itself offered few obstructions; the stairs emerged from an uncovered gap in the floor, rather than an upright door. From this place, then, the stars were as visible as they ever were on Earth.

The boy lay down in the center of the platform, heedless of his robes that might be dirtied, dropping his head to rest upon the rock-tiled floor; so that, except for a few half-seen crenellations of stone at vision's edge, and a sliver of crescent moon, reality became starlight.

The pinpoints of light in dark velvet twinkled, wavering and returning, a different kind of beauty from their steady brilliance in the Silent Night.

Harry gazed out abstractly, his mind on other things.

This day your war against Voldemort has begun...

Dumbledore had said that, after the Incident with Rescuing Bellatrix from Azkaban. That had been a false alarm, but the phrase expressed the sentiment well.

Two nights ago his war had begun, and Harry didn't know with who.

Dumbledore thought it was Lord Voldemort, returned from the dead, making his first move against the boy who had defeated him last time.

Professor Quirrell had put detection wards on Draco, fearing that Hogwarts's mad Headmaster would try to frame Harry for the death of Lucius's son.

Or Professor Quirrell had set up the entire thing, and that was how he'd known where to find Draco. Severus Snape thought the Hogwarts Defense Professor was an obvious suspect, even the obvious suspect.

And Severus Snape himself might or might not be even remotely trustworthy.

Someone had declared war against Harry, their first strike had been meant to take out Draco and Hermione both, and it was only by the barest of margins that Harry had saved Hermione.

You couldn't call it victory. Draco had been removed from Hogwarts, and if that wasn't death, it wasn't clear how it could be undone, or what shape Draco might be in when he got back. The country of magical Britain now thought Hermione an attempted-murderer, which might or might not make her decide to do the sane thing and leave. Harry had sacrificed his entire fortune to undo his loss, and that card could only be played once.

Some unknown power had struck at him, and if that blow had been partially deflected, it had still hit really hard.

And when Harry knew who...

...kill them?

No, said all the voices in Harry's mind that seized the moment to speak. Even his dark side, if it had a different opinion, remained silent. His dark side hadn't asked anything of him in exchange for saving Hermione, either. Maybe because his dark side wasn't an imaginary voice like Hufflepuff; Harry might imagine his Hufflepuff part as wanting different things from himself, but his dark side wasn't like that. His "dark side", so far as Harry could tell, was a different way that Harry sometimes was. Right now, Harry wasn't angry; and trying to ask what "dark Harry" wanted was a phone ringing unanswered. The thought even seemed a little strange; could you owe something to a different way you sometimes were?

In this quiet moment, the thought of killing off two-thirds of the Wizengamot seemed as foreign and as horrifying as the thought should properly have been, to any civilized eleven-year-old.

So, said another part of Harry, will you catch your enemy, and put him in a Dementor-free prison, and have him break loose and kill more people? Are you sure beyond reasonable doubt that you can safely hold Lord Voldemort himself, if not even Death stopped him before? If Professor Quirrell is a bad guy, what could possibly make him non-dangerous except killing him?

It was the sort of question you would be wise to decide in advance, if you were going to fight a war. If you needed to kill, you might not be able to spare a second to hesitate. Or if the wisest path was to obey Batman's code of nonlethality, you wanted to decide that while you were calm, not think it through in the middle of a battle.

Harry stared up at the random stars, the scattered twinkling lights that human brains couldn't help but pattern-match into imaginary constellations.

And then there was that promise Harry had sworn.