The door was pushed open, and a beam of light cut into the dark room.
Mrs Norris stepped inside with light, graceful movements, but in the darkness her green eyes did not shine the way a cat's normally would.
She moved with a clear purpose, as if something were guiding her, heading straight for the desk where the jack-o'-lantern sat.
The cloth covering the desk was yanked away, revealing the jack-o'-lantern wrapped in silver threads and flickering with a dim blue glow.
That cold blue light made Mrs Norris's furry face look especially sinister.
Using all four paws, she worked at the jack-o'-lantern with a patience completely unlike a cat's, trying to shove it off the desk.
The jack-o'-lantern was a little too heavy for a cat, but under her relentless prodding it crept bit by bit toward the edge of the desk, wobbling dangerously, on the verge of falling.
Excitement appeared on Mrs Norris's face, and the flames leaping inside the jack-o'-lantern grew visibly agitated as well.
Finally, the teetering jack-o'-lantern was pushed off the desk and crashed toward the hard floor.
To the cat's disappointment, however, it was not damaged at all. The silver threads wrapped around the pumpkin were not just decoration. They gave the jack-o'-lantern astonishing toughness.
It bounced a few times on the floor, then came to rest upright.
Perched on the desk, Mrs Norris froze.
The sealing effect was a little more unexpected than it had anticipated...
Inside the jack-o'-lantern, the shadow's thoughts moved sluggishly.
Since it could not escape at once, the top priority was to get out of this place as quickly as possible.
It needed a period of stable growth, at the very least enough to recover to the point where it could think normally again.
That required nourishment from the soul of a human wizard. Otherwise, all it could do was control this pitiful cat.
It manipulated Mrs Norris into jumping down from the desk, then pushed the jack-o'-lantern toward the door.
Before leaving, the shadow inside the lantern cast an unwilling glance at Ravenclaw's Diadem sealed inside the crystal, but in the end it had no choice but to give up.
Right now, it had no ability to take Ravenclaw's Diadem with it.
...
Outside the Hogwarts Great Hall, Filch watched Harris Raymons enter the hall, his face dark.
Harris Raymons was very young, so young that when he had still been a student at the school, Filch had already been working at Hogwarts for several years.
The student he had once envied and resented had now become a professor he had no choice but to look up to. To Filch, that felt like a kind of unbearable torment.
Jealousy and bitterness gnawed at his heart like ants.
It made him even more irritated by the cheerful, laughing students around him.
It was time to make things difficult for some unlucky soul.
Filch hurried to the castle hall and looked out the window at the weather, a vicious smile spreading across his face.
The weather was bad today. A fine, misty rain drifted outside the castle, and just then the team practicing Quidditch on the pitch had come back. Even though they were soaked through, their mood was still lively.
Gryffindor students...
Punishing a whole group like that would be difficult. Filch stayed quiet for a moment and hid off to the side, watching the large group of Gryffindors pass through the middle of the hall, leaving muddy footprints behind.
If Filch had to clean up those stains himself, it would take at least half a day.
But this time, Filch had no intention of doing the work personally.
After the main Gryffindor group had gone past, his gaze locked onto a red-haired student who was small, thin, and not quite keeping with the others.
He looked like... one of the Weasley children, the younger brother of those two little nuisances.
The moment Filch thought of George Weasley and Fred Weasley, the two troublemakers who were always causing problems for him, anger surged up in him.
Those two were too slippery. They almost never gave him a chance to punish them, and that infuriated Filch.
"If I can't deal with you two, can't I at least deal with your little brother?" Filch said as he stepped out of the corner and blocked Ron Weasley's path.
"Look at what you've done!" Filch shouted furiously. "You dirtied the castle. As punishment, you're going to mop this clean. No magic allowed!"
Ron Weasley, who had been walking with his head down, looked up blankly. Before he could even react, a mop had already been shoved into his hands.
He stood there for a moment, stunned. Then once he realized what was happening, his face filled with anger.
"I didn't do this. Why should I be the one cleaning it up?" Ron Weasley shouted.
"If I say you did it, then you did it. Get it cleaned up now, or you won't be attending the Halloween banquet..." Filch snarled, not caring in the slightest.
Of course he knew Ron Weasley was innocent, but did that matter?
No.
He just wanted someone to vent his resentment on, and while he was at it, get a little revenge on those two pests.
Watching Ron Weasley look aggrieved yet still forced to clean, Filch strode off in satisfaction.
It was about time. He should go inspect the castle and see whether there was anything else that had been overlooked.
Ron Weasley gritted his teeth and dragged the mop in sloppy circles across the floor. As soon as Filch left, he pulled out his wand and cast a Cleaning Charm.
He was not going to stupidly mop the floor by hand. He was not Filch, that idiotic Squib.
Casually tossing the mop aside, Ron Weasley glared at it, still full of irritation.
"Damn Filch..." he cursed inwardly as he headed for the dormitory through the corridor beside him.
Suddenly, he heard a strange sound.
"Gululu... gululu..."
It sounded like something rolling along the floor.
Ron Weasley tilted his head and listened as the sound drew closer, then spotted a cat around the corner ahead, rolling a jack-o'-lantern along the corridor.
"That's Filch's cat!" The moment he recognized it, disgust appeared on Ron Weasley's face.
Mrs Norris also stiffened when she noticed someone else there.
She'd been discovered. What now?
The flames inside the jack-o'-lantern flickered uneasily. A restless shadow twisted around the lantern, but the silver threads on its surface did not yield in the slightest, tightly restraining the power leaking from the shadow.
There was no getting away. That cat might be quick, but what use was that? The key issue was still the jack-o'-lantern sealing it inside.
Just as the shadow grew frantic, the student moved.
"Filch's cat... Hmph, you're just as annoying as your owner." Still sick with anger from Filch's treatment, Ron Weasley walked over without a second thought and kicked the stunned Mrs Norris away.
The blue flames inside the jack-o'-lantern shuddered involuntarily.
Why were Hogwarts students so irritable these days?