Professor Lupin talked to Harry about his own school days, all trivial matters, but Harry was quite fascinated as he listened.
When Professor Lupin mentioned graduating in the seventh year, he glanced at Sirius Black, as after graduation he was busy helping Dumbledore connect with other werewolves and wasn't aware of what had happened here.
By the time he heard the news, James and Lily were dead, Voldemort had fallen, and it seemed as if the once giant and terrifying force of the Death Eaters had collapsed overnight.
The werewolves he had been in contact with also retreated into their dark corners after losing many members, never to be found again.
By the time he finished speaking, Black had already descended from midair.
"Everything started with a prophecy..."
He sat on a tattered stool and, under everyone's gaze, slowly revealed the truth of that year.
Professor Trelawney made a prophecy about the Savior, saying that the child who could defeat Voldemort had been born. That year, there were two children born, and Dumbledore chose Harry in the end.
But somehow, the Death Eaters also got this information.
"It must have been Peter who leaked the secret..." Black said through gritted teeth, "Dumbledore instructed James not to let others know about this, but he still told us..."
"And what happened after that..." Harry asked eagerly.
"James and Lily took you and kept dodging the Death Eaters' pursuit," Black murmured, lost in memory, "Then they decided to adopt Dumbledore's suggestion, to use an ancient magic to protect you as you grew up.
The Fidelius Charm.
It's a magic that hides secrets within a person's heart, like the address of a house.
As long as the Secret-Keeper didn't voluntarily reveal James and Lily's location, even if Voldemort pressed his nose against the window, he wouldn't be able to see them."
Hearing this, Harry roughly understood what Black meant.
"So, Peter was the Secret-Keeper, right?"
"It's all my fault!"
Black suddenly began to hit his own head, saying hoarsely, "The Secret-Keeper was supposed to be me, but at the last moment, I persuaded Lily and James to switch to Peter... I thought it was a good strategy... A ruse, Voldemort would come for me instead and wouldn't think they'd use someone as weak and useless as Peter..."
"I'm the one who harmed Lily and James..."
Black grew more agitated as he spoke, but each time he gritted his teeth with hatred, he would remember Peter's current plight, and then burst into a hysterical laugh.
But even in laughter, Harry could not hear a trace of joy.
When Black calmed down again, amidst others' questions, he began to intermittently recount what happened next.
Including how he saw Scabbers' photo in the newspaper, recognized it as Peter, and how he used his Animagus form to escape from Azkaban and reached Hogwarts.
"So that dog was you!" Harry pointed at him and said.
"Yes, it was me." Black grinned, "I wanted to see you, so I went to Privet Drive. I'm sorry, I believe I startled you at that time."
Harry didn't know what to say... Black had frightened him more than once; because of that big black dog, he had been on edge for months.
"Sorry, Sirius." Lupin walked over and hugged him.
"Long time no see, Remus." Black reciprocated the hug, "You really should punch me."
"I was thinking the same." Lupin nodded and, without warning, punched Black in the face, "You should have told me all this sooner."
Black flew back and fell to the ground, but then he laughed again.
Professor Lupin walked over, grabbed his hand, and pulled him up, the two embracing once more.
"Forgive me, Remus..." Black said.
"Don't mention it, Padfoot, old friend." Lupin said, "Then can you forgive me for once thinking you were a traitor?"
"Of course." A brief smile flitted across Black's gaunt face.
"Sorry..."
Though reluctant to interrupt such brotherly emotions, it was already late, and Kael was not planning to stay in such a place all night.
He walked over and handed Black the cage with Scabbers in it.
"Now he's yours... but as compensation, you'll need to buy Ron a new pet, how about an owl?"
"Of course, no problem, it's what I should do."
Ron, who originally had a sour expression, lit up when he heard this.
They should have said it earlier…
If I'd known Scabbers could be exchanged for an owl, why go through all this trouble?
Taking the cage, Black's expression turned sinister, looking as if he was about to eat Scabbers, then he looked at Kael, about to express gratitude, when he suddenly remembered something...
"I think I've seen you before." Black said. "Remember? In Hogsmeade, you gave me a pack of beef jerky, the most delicious thing I've eaten in over a decade."
"Oh, that time." Kael feigned sudden realization, "You deserved it. Your performance jumping through rings of fire was amazing..."
The surrounding fell silent again.
"Jumping through rings of fire?" Professor Lupin gave Black a strange look, "You can do that?"
"Uh..." Black's eyes dodged, but he quickly regained composure, staring back sturdily.
After all, he was a dog at the time, what was wrong with jumping through rings of fire, plus it was to fill his stomach, nothing shameful.
"Ha..." Professor Lupin let out a low laugh, unusually clear in the cramped room.
As if lighting a fuse.
Ron and Hermione also turned their heads away, shoulders shaking.
"Pfft..."
Harry, who was immersed in the truth, couldn't help but laugh.
Perhaps knowing it wasn't right, he hurriedly covered his mouth and changed the subject: "What do you plan to do with Scab… Peter."
"Of course, kill him!" Black stared at the unconscious rat in the cage, "But leaving him as a rat forever is quite nice too!"
"Can he really not change back?" Harry asked in a low voice, "I mean... someone like him isn't worth turning you into a murderer.
And Peter is the true betrayer. If anyone deserves Azkaban, it's him, not you..."
Black's eyes were bloodshot, gasping heavily.
If he could, he'd certainly want to rid himself of those Dementors forever, for only by doing this could he openly care for Harry.
But the problem is, Black didn't know if Peter could change back...
Intuitively, everyone looked at Kael.
"In fact, he can." Kael said, "When wizards discovered an Animagus that couldn't return to human form, they studied relevant magic potions.
"Remember those who were petrified by the Basilisk in second year?"
Everyone nodded; Hogwarts was almost closed at that time, leaving a deep imprint on them.
"The Resurrection Potion that ultimately removed their petrification was invented back then, and that's also the only way to restore him."
"But..."
He looked at the surprised group and continued: "Before making any decisions, I think you should go see Professor Dumbledore.
Right now, everyone thinks you're the traitor, and Peter is the hero. No one will believe a traitor's story... you wouldn't even have a chance to defend yourself; the Dementors won't listen to explanations.
Unless you can persuade Professor Dumbledore to help you."
"You're right." Black also calmed down, "I'll go tomorrow."
"No need, you can go right now." Kael said, "He's a light sleeper, just knock on the door a few more times."