The Headmaster can feel when a student dies in Hogwarts. That's how he showed up the moment Hermione died.

But the Headmaster can also feel when a creature unknown to Hogwarts is in Hogwarts. That's how he showed up when Harry rejected his phoenix.

But so why didn't Dumbledore feel the troll and intercept it much sooner? I expect before long the Dumbledore-haters — both those in the story and those on Less Wrong and Reddit — will latch on to this as proof that Dumbledore has been evil all along.

The problem is, we know a thing or two about Hogwarts's wards by now. We know, for instance, that Salazar Slytherin was the one who wove them:

or by some entity which Salazar Slytherin keyed into his wards at a higher level than the Headmaster himself.

Salazar Slytherin's wards. Salazar Slytherin, who left a basilisk that knew all his secrets. Secrets that Quirrellmort now knows.

Dumbledore will try to tell the wizarding world that the only explanation of Hermione's death is that Voldemort was behind the attack. This will be seen by the world as the same thing Headmaster Dippet actually did when Myrtle died: the accusation of an unlikely — "preposterous!" — scapegoat.

And now, Lucius Malfoy is there to stir up the opposition:

Lucius Malfoy controls Minister Fudge, through the Daily Prophet he sways all Britain, only by bare margins does he not control enough of the Board of Governors to oust me from Hogwarts.

Those bare margins are about to be erased. For the first time in fifty years, a student has died in Hogwarts, and there is reason to suspect Dumbledore of involvement. Dumbledore is not going to be Headmaster for very much longer.

And the Philosopher's Stone is there, in Hogwarts, in the place, until now, of Dumbledore's own power.

Eliezer took the troll fight that a first-year Ron Weasley won in canon and turned it into the death of the #2 character in Methods. I can't wait to see what he does with this.