Looking at the frantically panicked Scabbers, Ron instinctively retreated to the wall, clutching his chest tightly with one hand, and hysterically asked, "What on earth is going on, can someone explain?"
Having raised a pet for years, and now seeing it use a wand, his mind was in chaos, and he dared not approach Scabbers again.
"That's what we want to know as well." Professor Lupin glanced at the still-laughing Blake and frowned, "How did you know Peter couldn't change back?"
Kael did not answer immediately but instead took out his wand.
"Stupefy!"
Peter, who was about to hit the wand, immediately fell to the ground.
Then Kael handed back the wands to Hermione and Professor Lupin before explaining, "Because of those supplements I brewed for it."
"Supplements?" Hermione furrowed her brow as she received her wand, "But the books never mentioned that pet supplements could prevent an Animagus from reverting to human form."
"Generally, they can't." Kael said, "But I added a whole dried Mandrake leaf to its supplements... and it was the one from the top of the root bulb."
"What did you say?" Professor Lupin instinctively raised his voice.
Mandrake leaves are not cheap to begin with, costing five Sickles per leaf, and the one on the root bulb is even more expensive, almost ten times the price of a regular leaf.
Such an expensive thing would be enough for him to live for a month, yet Kael used it to brew supplements for a rat?
Could it be that Kael had known Scabbers was Peter all along?
But that doesn't make sense... Professor Lupin shook his head. Only a few people had seen Peter as an Animagus, and Peter's fake death happened twelve years ago when Kael was only two or three!
"It was kind of a coincidence..." Kael didn't mind Professor Lupin's strange expression and continued, "I originally wanted the supplement to be more effective, but I didn't expect him to be an Animagus."
"But... does it matter?" Harry blinked in confusion.
"Of course it matters." Kael conjured a cage, trapped Peter inside, and said without raising his head.
He had thought someone would help explain, but after dealing with Peter, no one around said a word.
Even Hermione and Lupin stared at him with the same bewildered look as Harry.
"You never read herbology books beyond the textbooks?" Kael asked instinctively.
Hermione shook her head slightly; herbology was the subject she had read the least about among all her books.
Professor Lupin turned his head away; his situation was similar to Hermione's.
"Alright..." Kael sighed and could only continue, "Mandrake leaves are great for Fantastic Beasts, healing wounds, and enhancing physical strength... They have many uses, but for Animagi, it's different. You should know what the first step to learning Animagus is..."
Kael directed the last statement at Blake.
"Of course I remember." Blake, floating mid-air, didn't question how Kael knew he was an Animagus, but rubbed his sore jaw and said, "Hold a Mandrake leaf in your mouth for a month... Honestly, that month was miserable, and I almost gave up several times."
"Exactly."
Kael said, "The Mandrake leaf is meant to record all your information as a wizard; it's essentially another 'you,' or a guiding beacon..."
"What beacon?" Harry was bewildered.
He felt as if he were in Professor Trelawney's Divination class, understanding nothing, only feeling like he was participating for the sake of it.
"Alright, let me simplify it." Kael sighed, "The Greater Death's Head Hawkmoth chrysalis turns you from human to animal, while the Mandrake leaf can turn you back..."
"What is the Greater Death's Hea... ouch!"
Harry was about to ask more, but Hermione nudged him in the side with her elbow, making him wince in pain.
"That's a magic potion material." Kael glanced at him and continued, "So if an Animagus in animal form consumes a large amount of Mandrake leaves, the 'wizard' information in their body will gradually disperse until they can no longer change back."
"But that's impossible..." Hermione frowned, "Professor McGonagall taught us about Animagi, she never mentioned this point. If it were as dangerous as you say, the professor would definitely warn us."
"Because there's no need." Kael said, "Strictly speaking, it's tough for the 'wizard' information to disperse unless someone continuously eats it for years... and once they revert to human form, the information regathers.
There aren't many Animagi to begin with, and to be an animal for five continuous years while constantly consuming something containing Mandrake leaves, the probability is too low...
In a thousand years of the Magic Realm, only one person experienced this... oh no, now it's two."
Kael glanced at Peter in the cage.
Blake started laughing again.
Professor Lupin looked at Kael and suddenly asked, "Did you already know Scabbers was Peter?"
Kael turned, "Why do you say that?"
"Because I didn't see surprise in you." Professor Lupin said, "Whether it's me, Harry, Ron, or Hermione, we were all shocked when confirming Scabbers was Peter, but you were different, very calm."
Hearing this, everyone's gaze turned to Kael simultaneously.
Ron seemed to want to say something, but Hermione stopped him.
"I'm not surprised because it's not the first time this has happened." Kael shrugged.
"What?" Professor Lupin was taken aback, seemingly not expecting Kael to say that.
"In fact, something similar happened when I was in my first year; another student's pet was also an Animagus, and it was a rat as well."
Kael laughed, "If you don't believe me, you can ask Fred and George or any fourth-year or above student; they all know."
Everyone looked at each other, expressions rich with complexity.
Harry and the others started a year after Kael, so they naturally didn't know about this. With Professor Lupin only arriving this year, all he knew about past events was what other professors told him, mostly relating to Harry.
He hadn't inquired further back.
After hearing Kael's explanation, Harry nodded in understanding... honestly, if he saw a face growing on the back of someone's head now, he wouldn't be surprised either.
Soon, the room fell into silence, with only Blake's gradually hoarse laughter remaining.
Harry felt a bit awkward, hesitantly looking at Professor Lupin, wanting to ask something but not knowing how to start.
But his expression was easy to guess.
"Curious about Lily and James?" Professor Lupin asked.
"Yes." Harry nodded, "I heard you say earlier that you were friends."
"Best friends, at least to me." Professor Lupin said.
"Can you tell me?" Harry asked eagerly, "What happened, and what do you mean by Secret-Keeper?"
Professor Lupin hesitated briefly but nodded nevertheless...
"Alright, you have the right to know the truth, but I only know the beginning; you'll need Sirius to tell you the rest...
Let me think... I first met James and Lily during school..."
...