Although he had already witnessed several unfamiliar magical systems outside the tower—each one far beyond his comprehension—when Dumbledore finally stepped inside, even the seasoned centenarian could not suppress a quiet sense of awe.
From the outside, the structure appeared modest: a simple stone tower occupying no more than a hundred square meters.
But the moment he crossed the threshold, the space unfolded into something entirely different.
Before him stretched a vast, palace-like hall. The floor was covered with a Persian carpet so soft it felt like stepping on clouds. Dozens of floating orbs hovered overhead, each emitting a gentle white glow that illuminated the surroundings with warm clarity. Along both sides of the hall stood elegant spiral staircases, interspersed with several pitch-black doors that seemed to lead into unknown dimensions.
"An Undetectable Extension Charm?" Dumbledore wondered silently.
But he dismissed the thought almost immediately.
"No… that's not quite right. The Extension Charm merely stretches space. This… this structure is stable—almost self-contained. It has its own internal rules."
He narrowed his eyes slightly.
"This is more akin to that peculiar room I once encountered during a late-night walk at Hogwarts…"
The realization settled in his mind: the magical attainment of this tower's master was not inferior to his own.
"Please, sit, Headmaster Dumbledore."
Linn waved a hand casually.
Though no one was visible nearby, an exquisite velvet armchair slid smoothly into place behind Dumbledore as if guided by an invisible force. Moments later, a translucent, vaguely humanoid figure drifted forward, carrying a tray with two cups filled with a steaming, azure liquid.
"Invisible servants," Linn explained. "They have no physical form, so there's no need to worry about… contamination. This is my personal 'Focus Potion.' It's quite effective for restoring mental energy."
Dumbledore accepted the cup. The moment he tasted the drink, his eyes brightened.
"Remarkable," he said sincerely.
His sapphire gaze, magnified slightly by his half-moon spectacles, rested on the young man seated across from him. His expression was gentle, but there was unmistakable scrutiny beneath it.
"You appear to be no more than thirty," Dumbledore continued. "Forgive my curiosity, but I cannot recall seeing your name in any magical institution's records."
By this point, Linn had already dispelled the dozen or so layers of defensive magic that had been wrapped around him.
After a brief moment of internal deliberation—cross-referencing what he knew about this world, including its relatively weaker magical creatures, its peculiar spellcasting systems, and the identity of the man before him—he reached a conclusion.
This was, without question, the world of Harry Potter.
If that was the case, then what he needed most now… was a suitably mysterious and powerful identity.
"A name is merely a label," Linn said calmly. "You may call me Lynn Grey."
He had chosen the surname on a whim. In certain traditions, "Grey" represented neutrality—neither light nor dark.
"As for my background…" He paused briefly, recalling an image from another world—a divine embodiment of magic itself. "My mentor is a reclusive lady named Mystra. She has lived in seclusion for many years. I doubt you've heard of her."
"Mystra…" Dumbledore repeated thoughtfully.
He searched his memory, but found no trace of such a figure. Still, he did not press further.
"It seems the world is far larger than I once believed."
After a few more polite exchanges, the atmosphere in the hall gradually grew more serious.
Dumbledore set down his cup and cast a subtle glance around the room.
"Mr. Grey," he began, "judging by your surroundings, it seems you have been residing in seclusion within the Albanian forest for quite some time."
"Indeed," Linn replied, letting out a faint sigh. "It has been… ten years."
If only I had known this was the Harry Potter world, he thought bitterly. Would I really have spent ten years grinding monsters here?
"Ten years?" Dumbledore's gaze sharpened.
The timing was… significant.
It coincided precisely with the disappearance of Lord Voldemort at Godric's Hollow—and his rumored flight to Albania.
Dumbledore's tone remained calm, but an invisible pressure filled the air.
"Then there is something I must ask. During these past ten years… have you encountered anything unusual? A shadow, perhaps. Something that possesses animals. Something… steeped in malice."
Linn froze for a fraction of a second.
A shadow. Possession. Exile. Albania.
Fragments of childhood memories—books, films—clicked together in his mind.
If this truly was the Albanian forest… then the "shadow" Dumbledore spoke of could only be one entity.
Lord Voldemort.
And the thing I've done most over the past decade… Linn realized slowly… is kill that so-called "Demigod Lich" over and over again to level up.
His expression twitched.
No way.
That thing I treated like a practice dummy…?
The creature he had blasted apart with Magic Missile… shattered with Shatter… chased down whenever it tried to escape his barrier…
That was the Dark Lord?
The man whose name struck terror across the wizarding world?
Dumbledore noticed the subtle shift in Linn's expression. His grip on his teacup tightened ever so slightly.
"So… you have seen it?" he asked quietly. "Did it… harm you in any way?"
"Ah… yes," Linn admitted, rubbing his forehead. "I encountered it when I first arrived ten years ago. It couldn't be killed. Every time I dispersed it, it would reform shortly afterward."
"And then?"
"Then I used it as a test subject," Linn said with a shrug.
"In these ten years… I've probably 'killed' it a few thousand times. I didn't keep count, but roughly once a day. More, if I was in a bad mood."
He paused briefly.
"Until last summer, it finally seemed to collapse completely. It possessed a passing human while I was asleep and escaped. It hasn't returned since."
Linn sighed.
"A shame, really. It was a very useful training target."
"…"
Silence fell over the hall.
Dumbledore's hand trembled almost imperceptibly.
A few thousand times?
He had used Lord Voldemort… as a training dummy?
Even Dumbledore, who had witnessed countless extraordinary events, felt his composure waver.
He now understood why Voldemort had returned so weakened… so unstable.
Ten years of relentless destruction—even for a being like him—would break anyone.
Yet at the same time, Dumbledore felt an immense sense of relief.
This man was not Voldemort's ally.
That much was certain.
"Ahem."
He cleared his throat and regained his composure.
"I had feared that the shadow might harm innocent people," he said, his usual gentle smile returning. "But it seems… my concerns were unnecessary."
He stood and extended his hand.
"Mr. Grey, now that your… research subject has departed, would you consider a change of environment?"
"Hogwarts is currently in need of a Defense Against the Dark Arts professor. The previous professor… unfortunately passed away. We require someone of genuine ability."
Linn raised an eyebrow.
Defense Against the Dark Arts.
He knew the position well.
A cursed job. No one lasted more than a year.
But considering that the one who placed the curse had been repeatedly "grinded" by him for a decade…
The curse probably wouldn't work anymore.
And besides, if he wanted to advance further—to reach higher levels of magical mastery—he needed knowledge, not just combat experience.
"I have two conditions," Linn said, raising two fingers.
"Please, go on."
"First, I want unrestricted access to the Restricted Section of the Hogwarts library."
He smiled faintly.
"I am very interested in your world's magical system."
"Second, the salary must be sufficient."
He gestured toward his surroundings.
"My research is… expensive."
Dumbledore nodded without hesitation.
"Both requests are entirely reasonable. Hogwarts has always supported those who pursue knowledge."
A glint of amusement flickered in his eyes.
"As for the salary… while it may not rival that of a Gringotts manager, it will be quite respectable."
The two exchanged smiles.
An agreement had been reached.
Before departing, Dumbledore's gaze lingered on Linn's empty hands.
"One last question," he said. "Your spellcasting method… appears to function without the use of a wand. That is quite rare."
"Wands?" Linn chuckled.
"In my homeland, we believe that magic originates from within—not from external tools."
He raised his hand slightly. A complex arcane pattern briefly flickered into existence at his fingertips before vanishing.
"My body is the vessel. My will is the guide. Compared to that… relying on a wooden stick seems rather limiting."
Dumbledore watched closely, deep in thought.
"Fascinating," he murmured. "I would very much like to study this method in the future."
"Of course."
"Then let us depart."
Dumbledore adjusted his robes and extended his arm.
"We'll be Apparating. It may feel… uncomfortable."
Linn frowned slightly.
He knew of Apparition. Crude. Inelegant.
Compared to his own teleportation spells, it was practically torture.
But without knowledge of the destination, he had little choice.
Reluctantly, he grasped Dumbledore's arm.
With a sharp crack, the world twisted—
And they vanished.