"Transfiguration had many applications in combat, such as changing the battlefield or casting a Transfiguration spell directly on your enemy."
Professor McGonagall strode down a corridor in the castle.
Devero hurried after her.
"But the most common application, and also the most difficult, is animating stone statues."
"For this kind of Transfiguration to be useful in combat, it takes years of preparation. That doesn't just mean building up your skill with the spell."
As she spoke, Professor McGonagall arrived at a wall on the second floor of the castle.
She gently nudged a wall sconce that wasn't lit.
At once,
the wall in front of them vanished.
A low passage was revealed.
Devero watched as it appeared.
He was utterly astonished.
There had been no mention of a passage like this in the original story.
And Professor McGonagall knew about it.
It seemed there was still a long way to go before he could fully explore Hogwarts Castle.
The two of them then entered the low passage.
Professor McGonagall had to bend over to pass through it.
Devero only just managed.
"Preparation also means having the right materials for Transfiguration. You can't expect a bedspread to become a powerful weapon just because you've enchanted it."
At this, Professor McGonagall glanced back with a smile.
"Of course, if you have an enormous amount of magic, then the materials aren't quite so important."
Devero nodded slightly.
But he had his doubts about the professor's claim that a bedspread couldn't do any damage.
He'd heard other Slytherins say
that Goyle's bedspread had taken only a week
to start giving off a truly terrifying smell.
Living with him had been like enduring the Cruciatus Curse nonstop.
A beam of light shone down the passage ahead,
and the view suddenly opened up before Devero.
"We're