Time passed quickly, and in the blink of an eye, a week had gone by since the Chamber of Secrets incident.
That night, Hermione and Kai Adler had remained by the lake until late. Hermione had been so enamored with her Patronus that it was nearly curfew before she finally, albeit reluctantly, returned to the common room.
Harry and Ron, still sheepish, apologized profusely—convinced that their impulsive fireworks display had ruined Hermione's birthday.
But Hermione thanked them both without hesitation.
After all, they had genuinely tried to make her happy.
And when the two returned to their dormitory still looking uneasy, Kai, in a rare moment of lightheartedness, agreed to teach them spells.
He had no desire to hoard knowledge, and despite their blunders, he truly saw them as friends.
Thus began a new nightly routine—attending classes during the day and training deep in the Chamber of Secrets after hours.
Of course, with Harry and Ron joining, Kai could no longer simply Apparate in and out. Instead, they returned to the original method: entering through the girls' bathroom on the fifth floor.
Harry and Ron were obviously confused and amazed, but Kai brushed it off with a casual explanation that his guardian was none other than Professor Dumbledore.
Predictably, the two were left gaping in astonishment.
But by now, they had long grown used to Kai's mysterious nature. One more secret barely registered.
That evening, Hermione and Harry were in the distance practicing spells.
Hermione was reinforcing the more intricate ones, while Harry—less confident with foundational magic—was still working on the spells in The Standard Book of Spells, Grade 2 before advancing to more difficult enchantments.
Ron, unfortunately, was having a rough time. His wand had broken earlier in the year, and now even basic charms failed, often backfiring on him.
So, Kai had given him a task he loathed: memorizing magical theory.
Ron sat slumped in a chair, staring at the thick, ancient textbook in front of him, looking utterly defeated.
Every letter made sense—yet somehow, none of the sentences did.
He looked like a man contemplating exile.
"If you need the lavatory, it's upstairs," Kai said casually, looking up from his own reading.
"I'm not going to the bathroom!" Ron barked.
Kai smirked. "Then why do you look like you're in agony?"
"The book," Ron grumbled, slapping the heavy tome. "These bloody books are impossible."
Kai took a sip of his tea, then looked back up, amused. "You might want to treat those books with a little more respect."
"Why?"
"They're relics," Kai said, gesturing to the books around them. "Recovered from this very chamber. They belonged to Salazar Slytherin himself—over a thousand years old."
Ron blinked. "Wait—these are his books?!"
Before Kai could say another word, Ron had already flung the book away like it was cursed.
Kai flicked his wrist lazily. The book spun through the air and landed in his palm.
"Careful," he said mildly. "You're lucky that one wasn't bound in basilisk skin."
"But it's Slytherin's!" Ron looked genuinely spooked. "What if there's something… dark in it?"
Kai let out a slow breath and fixed him with a flat look. "Ron, the chair you're sitting on? Also his."
Ron leapt up like he'd been shocked.
Kai chuckled softly. "Fun fact: the Hogwarts castle was built by all four founders. Slytherin's influence is everywhere. Want to drop out?"
Ron flushed.
"I mean… he was kind of the original Dark Wizard, wasn't he?"
"In your mind, yes. But his actual views and values? History tends to be told by the victors. His legacy is… more complex."
Kai leaned back in his chair, legs crossed, swirling the last of his tea like a seasoned nobleman.
"Regardless of what kind of person he was, the knowledge he left behind is invaluable."
He floated the book back to Ron's desk.
"That's what matters."
Ron still looked hesitant, eyeing the book as if it might bite.
"What if there's Dark Magic in it?"
Kai gave a faint, dangerous smile.
"What of it?"
"Magic, dark or light, is just a tool. It's the wizard who uses it that defines its purpose."
He tilted his head thoughtfully.
"Someone could use the Killing Curse to destroy Voldemort. Would that make them a villain, or a hero?"
Ron stared at the book again, brow furrowed.
Kai didn't press him further, simply resumed sipping his tea, eyes full of amusement.
"Kai !"
Hermione's voice rang out.
Kai turned. At once, his reserved smile softened into something warm and genuine.
"Finished your training?"
"Mm-hmm!" Hermione skipped over, vibrant as a sunbeam, her curls bouncing behind her. Her clear eyes sparkled as she looked at him—at no one else.
"I finished everything you assigned!"
She placed a hand on his shoulder, casual, affectionate. Something between them had clearly shifted.
Kai took her hand gently in his, fingers brushing hers.
"How does it feel?"
"Brilliant!" she beamed. "So many spells feel easy now. I even completed the full form of Feuerpfad! Not very strong yet, but still!"
Her excitement was childlike, infectious.
"This is the best birthday gift I've ever gotten."
Kai shook his head lightly. "Life's long. There'll be better ones yet."
Hermione blinked at him, confused.
Kai didn't explain. He just gazed at her, a cryptic smile playing at his lips.
Hermione blushed faintly. She cleared her throat and quickly changed the topic.
"What were you and Ron talking about?"
"Nothing much," Kai said, pulling her down to sit on the armrest beside him.
Hermione leaned into his shoulder, comfortable, unconcerned, even rubbing her cheek lightly against his robe.
"Just some advice."
"Advice for what?"
Harry, who had been watching them with a look of long-suffering patience, saw his moment.
He glanced toward Ron, who now appeared unusually focused on the book in front of him.
Kai answered. "Ron's been carrying guilt over what happened in the Chamber last week."
Harry nodded. "He's been down lately. I've told him it wasn't his fault."
"It wasn't," Kai agreed. "But guilt doesn't always listen to logic."
"So what'd you say to him?" Hermione asked.
Kai looked at her, hesitating for a moment.
"I gave him an idea," he said at last. "Something to work toward."
Before Hermione could press further, a sudden burst of firelight appeared beside them with a loud crackle.
A tall figure stepped from the flames, dressed in deep robes of royal blue, white beard flowing.
"Professor Dumbledore!"
Hermione jumped to her feet, flustered by her own proximity to Kai.
Kai, too, stood quickly. "Professor Dumbledore? To what do we owe the pleasure?"
Dumbledore's expression was unusually grave.
"Kai," he said calmly. "I need you to come with me."
Kai's brow lifted slightly. "What's happened?"
The headmaster's eyes swept briefly over the group, lingering on Ron for the barest moment.
His gaze returned to Kai.
"It's about Grindelwald."
Harry's eyes widened. Ron looked up sharply.
Kai tilted his head, expression unreadable.
"Well, well," he murmured. "You've certainly piqued my interest, Professor."