Harry Potter and the Methods of Rationality

"No, not that part," said Professor Quirrell. His voice grew a little stronger, took on some of its normal lecturing tone. "An ordinary Charm, Mr. Potter, can be cast merely by speaking certain words, making precise motions of the wand, expending some of your own strength. Even powerful spells may be invoked in this way, if the magic is efficient as well as efficacious. But with the greatest of magics, speech alone does not suffice to give them structure. You must perform specific actions, make significant choices. Nor is the temporary expenditure of your own strength sufficient to set them in motion; a ritual requires permanent sacrifice. The power of such a greater spell, compared to ordinary Charms, can be like day compared to night. But many rituals - indeed, most - happen to demand at least one sacrifice which might inspire squeamishness. And so the entire field of ritual magic, containing all the furthest and most interesting reaches of wizardry, is widely regarded as Dark. With a few exceptions carved out by tradition, of course." Professor Quirrell's voice took on a sardonic tinge. "The Unbreakable Vow is too useful to certain wealthy Houses to be outlawed entirely - even though to bind a man's will through all his days is indeed a dread and terrible act, more fearsome than many lesser rituals that wizards shun. A cynic might conclude that which rituals are prohibited is not so much a matter of morality, as habit. But I digress..." Professor Quirrell made a brief coughing sound, a clearing of his throat. "The Unbreakable Vow requires three participants and three sacrifices. The one who receives the Unbreakable Vow must be one who could have come to trust the Vower, but chooses instead to demand the Vow from them, and they sacrifice that possibility of trust. The one who makes the Vow must be someone who could have chosen to do what the Vow demands of them, and they sacrifice that capacity for choice. And the third wizard, the binder, permanently sacrifices a small portion of their own magic, to sustain the Vow forever."

"Ah," Harry said. "I'd wondered why that spell wasn't used all over the place, every time two people have difficulty trusting each other... although... why don't wizards on their deathbeds charge money to bind Unbreakable Vows, and use that to leave an inheritance for their children -"

"Because they are stupid," said Professor Quirrell. "There are hundreds of useful rituals which could be performed if men had so much sense; I could name twenty without stopping to draw breath. But in any case, Mr. Potter, the thing about such rituals - whether or not you choose to term them Dark - is that they are shaped to be magically efficacious, not to appear impressive when performed. I suppose there is a certain tendency for the more powerful rituals to require more dreadful sacrifices. Even so, the most terrible ritual known to me demands only a rope which has hanged a man and a sword which has slain a woman; and that for a ritual which promised to summon Death itself - though what is truly meant by that I do not know and do not care to discover, since it was also said that the counterspell to dismiss Death had been lost. The most dread chant I have encountered does not sound even a hundredth as fearsome as the chant you composed for Miss Davis. Those among the bullies who had a passing familiarity with Dark rituals - and I am certain that there were some - must have been terrified beyond the capacity of words to describe. If there existed a true ritual which appeared that impressive, Mr. Potter, it would melt the Earth."

"Um," said Harry.

Professor Quirrell's lips twisted further. "Ah, but the truly amusing thing was this. You see, Mr. Potter, the chant of every ritual names that which is to be sacrificed, and that which is to be gained. The chant which you gave to Miss Davis spoke, first, of a darkness beyond darkness, buried beneath the flow of time, which knows the gate, and is the gate. And the second thing spoken of, Mr. Potter, was the manifestation of your own presence. And always, in each element of the ritual, first is named that which is sacrificed, and then is said the use commanded of it."

"I... see," said Harry, as he trod through the halls of Hogwarts after Professor Quirrell, following him toward the Defense Professor's office. "So my chant, the way I wrote it, implies that the Outer God, Yog-Sothoth -"

"Was permanently sacrificed in a ritual which but briefly manifested your presence," said Professor Quirrell. "I suppose we will discover tomorrow whether anyone took that seriously, when we read the newspapers and see whether all the magical nations of the world are banding together in a desperate effort to seal off your incursion into our reality."

They walked on, as the Defense Professor began chuckling, odd throaty sounds.

The two of them didn't talk after that until they came to the Defense Professor's office, and then the man halted with his hand upon the door.