From Azkaban to Hogwarts.

'It wasn't aimed at Harry…it might even have existed before Percy enrolled; the chances of it encountering Harry are too low, no one could have guessed it.'

'Then it was most likely killed a long time ago…'

"My God! What's going on here?" Professor McGonagall's voice came from afar, followed by the sound of hurried footsteps running down the corridor.

A moment later, Professor McGonagall appeared in front of the door that no longer existed.

She pointed her wand into the room, her eyes slightly puzzled. "Are you alright, Professor William? And Potter, what happened to him?"

The story was too complicated to fit on a note, so she was still completely confused.

"I'm fine, Professor McGonagall."

William tried to appear to be smiling. "There's something I need your help with. I have a terrible suspicion, but I'm at a loss about how to fix it."

"problem?"

Professor McGonagall paused, completely forgetting about the door she had been about to ask. She looked at Harry with a puzzled expression, "What trouble has Potter gotten into?"

"No, what's giving me a headache is a mouse, a pet mouse."

William shook his head and took a few steps to the table where the freckles were placed. "This is it, Professor."

"mouse?"

Professor McGonagall followed, bewildered, and then looked at the table in the direction William gestured—there, a rat lay unconscious, seemingly badly injured, but its wounds were healing and growing rapidly, clearly having been given an expensive potion.

But what's so interesting about rats?

If the person who caused this scene were Gryffindor, Professor McGonagall would have even considered it a prank.

But she soon noticed something was wrong—this mouse, whether in its fur, claws, tail, or anything else, looked exactly like a normal mouse, but it wasn't a mouse.

'A very clever transformation technique...it almost fooled me...'

"I'm not entirely sure, what do you think?"

Professor McGonagall did not respond. She waved her wand, and a few hairs fell from the rat's body and floated into the air.

But nothing happened; the mouse's short fur eventually floated lightly to the ground, where it remained motionless.

“Your guess is correct, Professor William.”

Professor McGonagall took a breath and nodded, her expression also turning grim. "While further research is needed to confirm which type of mutation it is, there is no doubt that this rat is not a rat."

Where was it discovered?

"Use your wand to pick up the mouse fur again," Professor McGonagall asked with a serious expression.

“It’s Ron’s pet, Scabbers. It got injured today, and Hagrid suggested I bring it to Professor William for treatment…”

Before William could respond, Harry, as if startled, blurted out all the questions.

"Percy's pet, and then gave it to Ron?"

Professor McGonagall repeated the confirmation as she waved her wand—a transparent cat emerged from it, stomped in mid-air, and then charged straight toward the wall.

Upon seeing this, even Harry, who was usually quite easygoing, immediately realized that something terrible had happened.

"Does it usually live in the lounge?"

Harry paused for a moment, then realized the professor was asking him. "Yes, Professor, he's been living in the common room since his first year, and he's been staying there even longer this year because he's in such poor condition."

"Does it usually exhibit aggressive behavior? Or does it do anything that is unusual for a mouse?"

Harry thought about it carefully. "No, Professor, it just doesn't bite like a normal rat, but that's a common trait of pets."

"What about break time? What's the menu like?"

"... "

One question after another was posed, and Harry had to think carefully from time to time before he could answer them.

"Professor, it's me."

Percy's voice was tinged with fear. He stood in William's doorway, which had no door, looking at the two professors inside, his expression slightly tense.

"Come in, Percy."

William nodded at him. "Come over here. Do you recognize this mouse?"

"Blemishes?"

Percy exclaimed in surprise, "What's wrong with it?"

"It was slightly injured, so Harry brought it over, but it's still receiving treatment. Harry said it used to be your pet?"

"Yes, Professor."

Percy nodded, thought for a moment, and said, "I've had it since I was very young, so it's been with us for twelve years now."

"Twelve years? Where did you get it from in the first place?"

“A pet store,” Percy blushed, “where the mice were on sale…”

William had some understanding of the Weasley family's situation and immediately realized that they had bought Scabbers simply because it was cheap.

"Then what about its toe? Why is one of its toes missing?"

"It was like this when I bought it... because it was missing a toe, it was cheaper..."

Percy blushed even more.

Everything makes sense now—transformation, cheap sales…

However, he couldn't be allowed to go back yet. Although William was certain that it wasn't their family who did it, they still had to see what Professor McGonagall had to say. Just as he was questioning Percy, Professor McGonagall had already begun investigating what kind of transfiguration had caused such a consequence.

"Unexpected..."

When Professor McGonagall looked up, her eyes were filled with rare surprise: "Not Transfiguration... it's Animagus."

Animagus?

What kind of transformation is this?

Although William has been working hard to learn Transfiguration, he is still struggling with animal transformations, let alone more complex human transformations—as for Animagus, a form that even the Transfiguration professors find surprising, William has not even touched upon it.

"Animagus?"

Percy was taken aback. "But Professor, didn't you say that only seven wizards in this century have mastered this spell?"

Seven...

William suddenly understood why he didn't know—even black magic rarely goes this far, being limited to only seven people.

“It’s obvious that this is an illegal Animagus, and the level of proficiency and success is extremely high.” Professor McGonagall nodded. “I would even say that, in terms of Animagus shapeshifting ability alone, he is better than me.”

'You can do that too…'

Although Professor McGonagall spoke casually, and William knew it was unlikely she wouldn't, he still couldn't help feeling like a salary thief who had snuck in compared to the other professors…

"Stronger than you?"

“Yes, I didn’t even recognize him at first…” Professor McGonagall shook her head. “We’ll have to find Albus. I can’t undo this level of Transfiguration.”

"I'll leave this to you, Professor William. I need to go to Albus's office myself."

Professor McGonagall nodded to William, then quickly left the room, her footsteps making a particularly loud noise in the hallway because there was no door.

'That method of using a Patronus to deliver a message was quite good; I'd like to consider it—but why did Professor McGonagall personally go to see the Headmaster? Was she afraid she wouldn't be able to explain things clearly, so the Headmaster pretended not to be at the school?'

Upon learning that it wasn't a human transformation, William suddenly felt like joking around, and he even made a few lighthearted jokes about the two principals.

Being imprisoned by someone else and being controlled by one's own shapeshifting magic are two different things. The former evokes a sense of shared sorrow, while the latter...

"Just how difficult is it to become an Animagus? Azkaban was talking about human transformations, but according to Professor McGonagall, Animagus is much harder than human transformations. Seven people in a century... Hogwarts has two..."

Although Professor McGonagall didn't say that Dumbledore was an Animagus, William implicitly acknowledged that the headmaster was skilled in magic—it would be strange if Dumbledore didn't know any kind of magic.

"Professor? So, Banban was turned into a rat by someone?"

After hesitating for a moment, Harry finally asked the question—he wasn't stupid, and it was too easy for him to come to this conclusion based on the professors' discussion and his conversation with Percy.

That's basically it.

William nodded—as long as it doesn't involve erasing memories or illegal imprisonment, this matter can still be discussed, since the impact isn't that great.

"So, was it damaged like this by bad people?"

Harry hesitated for a moment, then continued to ask.

“Cannot confirm…” William shook his head. At first, he was also influenced by that feeling of shared sorrow, but now that he was distracted, he had more things on his mind.

“You need to know, Harry, don’t easily trust things that are sealed away, especially if the other party is intelligent.” William then looked at Percy. “You should remember that too, Percy.”

"Learn to make your own judgments instead of accepting what the sealed people and things say. Even if there is truth serum, lying is very easy, and they can even tell only part of the truth and mislead you elsewhere."

"So, it was a bad guy, which is why it was turned into a rat?"

Harry still didn't understand.

"Learn to judge. We know nothing now, so we must proceed from reality. Blindly relying on first impressions is the most unreliable thing to do."

William reiterated, "But we'll have the results soon; the principal and the others are here."

Chapter 296 Little Pettigrew

The mouse named Scabbers was sent to Dumbledore's place, while its owner, Ron Weasley, was discharged after spending one night in the hospital.

William had expected Ron to make a huge scene demanding the return of his rat, but perhaps because Dumbledore was going to do it himself, a week passed and nothing happened.

"yawn."

In the faculty lounge, William yawned and put away his books and papers.

"Tomorrow is the weekend, you can't just keep reading and studying, William."

Adams said to William as he put away the beans he had been shelling all afternoon.

“I finally have an interesting theory, and I want to perfect it as soon as possible,” William replied, stretching. “I’d rather not go on the weekend. I just want to stay at school right now. Being watched by those black guys every time I go in and out is not a comfortable experience.”

"Can't you use the Guardian Angel Spell?"

“Being able to use it doesn’t mean I don’t hate it,” William spread his hands. “When I see them, I can’t help but want to use my Guardian Angel. Under that suffocating feeling, I can’t even control what kind of magic I use.”

"Using them once or twice could be considered an accident, but if you see them and immediately put your guardian spirit on your head, I reckon the Ministry of Magic will send me a letter within a week."