The next day, the four of them made their way to the Great Hall for dinner, as usual.
Kai Adler listened with amusement as Hermione grumbled about the overly sweet treacle tart served that day, a fond smile playing on his lips. His gaze casually drifted over to Harry and Ron, who—for once—seemed entirely normal.
They weren't whispering, shooting glances, or showing any signs of mischief.
Why are these two behaving so well all of a sudden?
Kai narrowed his eyes slightly, keeping an eye on them through dinner and the following classes. But surprisingly, nothing unusual happened all day—not even a prank.
Not during Potions, not during Transfiguration, not even in Herbology.
Strange. Are they giving up? he mused.
But they didn't look defeated. If anything, they seemed oddly energized.
Something's coming, he concluded. Probably during the last period.
Indeed, Defense Against the Dark Arts would be the final class of the day—and the best opportunity.
Kai wasn't particularly concerned. After all, he had told them he'd only teach them spells if they gave Hermione a birthday surprise she'd remember.
He hadn't meant anything grand. He just wanted Hermione to smile.
Whatever idiotic thing the two of them were planning—as long as it wasn't dangerous—he'd go along with it.
After all, when it came to Hermione's birthday, the real surprise… would be him.
Hermione, meanwhile, was sneaking glances at Kai every few seconds, her heart a swirl of emotions.
Does he know…?
Today was her birthday. But all day, Kai had acted the same as always.
No hints. No clues. No knowing looks or secret smiles.
Her heart twisted with worry. Maybe he forgot…
She didn't want to ask. What if he was planning something? She'd ruin it by asking.
But what if he truly had no idea?
That thought made her feel a little cold.
From the podium, Professor Dumbledore took in the unspoken drama between the two with a knowing smile, but said nothing. Instead, he closed the lesson book in front of him.
"Class dismissed."
Chairs scraped, wands were tucked away, and the students began to shuffle toward the door.
Kai stood slowly, his expression unreadable. Hermione followed a few steps behind, chewing her lip and hesitating.
Finally, she couldn't take it anymore.
"Kai, today…" she began, her voice soft and uncertain.
But just as she spoke, a loud crack interrupted her.
And then—fireworks.
Brilliant sparks exploded above their heads the moment they stepped out into the corridor.
Crimson comets and silver streamers filled the hallway, whistling and popping in all directions.
Even Dumbledore, who had just stepped into the corridor, raised his eyebrows in surprise.
Hermione's heart skipped. She turned to Kai, eyes wide and hopeful.
Did he do this? Was this his surprise?
Kai caught her gaze and understood immediately. But before he could speak, two familiar figures jumped out.
"Happy birthday, Hermione!" Harry and Ron shouted in unison.
Hermione blinked. "You…?!"
"That's right!" Ron beamed. "We put this all together just for you!"
Hermione turned toward Kai again, but his small sigh and helpless shrug told her all she needed to know.
It wasn't him…
A flicker of disappointment passed through her eyes—but she quickly pushed it down and smiled politely. "Thank you."
Kai's lip twitched. Just as he opened his mouth to say something, the hallway erupted into chaos.
The fireworks—initially charming—were now firing in erratic bursts. Some zoomed straight up into the stone ceiling, exploding in showers of sparks that rained down dangerously on the students.
Screams and laughter mixed in the narrow space. The sparks, still burning hot, singed robes and startled more than a few young witches.
Worse still, some of the larger fireworks packed enough force to knock over furniture or trigger minor magical reactions in student wands. What had started as a spectacle was quickly turning into a safety hazard.
Students ducked and scrambled. The corridor was filled with smoke, sparks, and panicked shouting.
Those nearest to the four of them had already heard the earlier exchange—realizing this was meant for Hermione's birthday.
"They did it!" someone yelled, pointing toward Harry and Ron.
Instantly, all eyes turned toward them.
Even Professor Dumbledore's sharp gaze landed squarely on the four students.
Harry and Ron went pale, stiff as boards.
Kai sighed and gently pulled Hermione backward, out of view and behind the classroom door.
"Don't say anything," he murmured with a quiet glance.
A moment later, the world spun.
By the time Harry and Ron turned to look for help, Kai and Hermione had vanished.
They reappeared outside, near the edge of the Black Lake. It was quiet, far removed from the chaos inside the castle.
The sky was painted with streaks of scarlet and violet as the sun dipped behind the mountains. The surface of the lake shimmered in molten gold and rose-red.
Kai led her to the shoreline, where they sat side by side, the only sounds the lapping of water and the distant cry of birds heading home.
"Did you tell Harry and Ron to do that?" Hermione asked, watching the light ripple across the lake.
Kai smirked, "Sort of. But how did you guess?"
Hermione gave him a sly side-eye. "If you weren't guilty, why did you Apparate us out of there like fugitives?"
Kai shrugged innocently. "I was avoiding trouble."
"Scared of being scolded by Professor Dumbledore?"
"Please." Kai snorted. "Would I be afraid of that old man?"
"Call him Professor."
"Yes, yes," Kai said with exaggerated obedience. "Anyway, I didn't expect them to use fireworks indoors. I just told them to make you smile. That was… not what I had in mind."
Hermione pouted, "How did you even know today was my birthday?"
Kai scratched the back of his neck. "Your parents wrote to me. They were worried you might feel lonely."
Hermione blinked, caught off guard. Her gaze flickered to his face, then down to the lake.
Her voice dropped a little. "So… you knew. And you just let someone else give me a surprise."
Kai watched her with quiet amusement. Why do I feel like the one who's in trouble?
Also, calling your two best friends 'someone else'? If they heard that…
He leaned closer, eyes glinting.
"Of course not."
He reached into his robes. "I've prepared something for you."
Hermione's eyes lit up instantly, though she tried not to show it. "Actually… I don't really need anything."
"Is that so?" Kai raised a brow. "Good. Because it's not much of a present anyway."
Hermione narrowed her eyes at him. "Really?"
He nodded. "Really."
Her expression shifted. The playful energy vanished. Her heart told her—this was something important. Something serious.
"…What is it?"
Kai didn't answer immediately. He turned his gaze toward the lake, now dyed in deeper crimson.
Hermione stared at him, waiting.
After a long pause, he spoke.
"One word," he said.
"Me."
Hermione blinked. "Huh?"
Kai turned to face her fully, his expression calm and unwavering.
"What I mean is… the birthday present I've prepared—is me."