The Order of the Phoenix's Invitation

Lin Du curiously examined the seemingly ordinary diary. "What is this...? I can feel an unusual dark aura from it, yet it just looks like a regular diary."

"It is indeed very good at disguising itself," Dumbledore's voice was low. "Just last night, it almost completely controlled Ginny Weasley, a first-year student."

Lin Du's expression immediately turned serious. "What did it do to her?"

"It's using her emotions and fears, slowly eroding her will," Dumbledore's tone carried a rare anger.

"It's draining her life force, trying to reconstruct its physical body through her. If it hadn't been discovered in time, this girl could very well have become a sacrifice for its resurrection."

A hint of coldness flashed in Lin Du's eyes. "So what exactly is this?"

"This is Tom Riddle's diary," Dumbledore said slowly. "Or rather, a Horcrux."

The moment the word "Horcrux" was spoken, the air in the office seemed to freeze. Lin Du abruptly stood up, then forced himself to sit back down.

"Voldemort's Horcrux?" His voice was filled with disbelief. "He hid a piece of his soul in such a... inconspicuous little book?"

"Don't be fooled by its appearance," Dumbledore said. "It is precisely this seemingly harmless disguise that allows it to easily approach unsuspecting students."

Lin Du gazed at the black diary on the desk, a flicker of understanding in his eyes.

He looked up at Dumbledore, his tone calm:

"So tonight's conversation, from the very beginning, was a test. You needed to confirm what choice I would make after learning of the Horcrux's existence."

Dumbledore did not deny it. "Once the secret of the Horcrux is leaked, those Death Eaters who believe Voldemort is dead will regroup. This is not loyalty, but fear—the fear of Voldemort has penetrated their very bones."

"As long as Voldemort shows any sign of a possible return, they will act immediately," Lin Du interjected. "Therefore, keeping the secret of the Horcrux is paramount."

Dumbledore nodded gently. "Voldemort gained an immortal soul through the Horcrux, yet he fears this secret being known. Even his most loyal Death Eaters do not know of the Horcrux's existence."

Lin Du's fingertips lightly tapped the desk. "And now, you've decided to entrust this secret, which not even Professor McGonagall knows, entirely to me."

"As Voldemort's shadow began to reappear, you happened to emerge," Dumbledore's gaze was deep. "And you, having only taught at Hogwarts for two months, have already uncovered the truth about the Basilisk. This makes me willing to believe that you might become an important factor in fighting Voldemort."

Lin Du stared at the diary emitting an ominous aura, and suddenly let out a scoff:

"Honestly, Headmaster, I've always felt Voldemort was far inferior to Grindelwald."

Dumbledore's fingers paused lightly on the tabletop, his gaze behind his half-moon spectacles flickering slightly.

"Grindelwald at least had a decent ideal—for the greater good," Lin Du's tone was clearly sarcastic. "Mad, perhaps, but with grand ambition. But this Mr. Voldemort?"

He pointed to the Horcrux on the desk. "Obsessed with pure-blood nonsense all day, turned himself into a noseless freak, and insists on tearing his soul apart and hiding it everywhere. With that kind of skill, he dares to call himself the Dark Lord?"

Dumbledore's expression was somewhat complex. "Every era has its unique darkness."

"Unique darkness?" Lin Du raised an eyebrow. "If you ask me, if Grindelwald knew his successor was this kind of character, he'd probably laugh himself to death in Durmstrang."

Hearing the name Durmstrang, Dumbledore's eyes went momentarily distant before returning to calm. "Perhaps. But for now, we must first deal with the trouble left behind by this 'unqualified' Dark Lord."

Lin Du stood up and drew his wand. "You're right. Let's quickly dispose of this embarrassing thing."

A hint of approval flashed in Dumbledore's eyes. "I noticed you were researching Fiendfyre."

"Indeed," Lin Du had already drawn his wand. "Fiendfyre is one of the few powers capable of completely destroying a Horcrux."

The search for the book title was unsuccessful. You might try searching for the author. Perhaps the name was just changed!

Dumbledore waved the Elder Wand, casting a stronger protective enchantment around the diary. "Please."

Lin Du closed his eyes. When he opened them again, the tip of his wand was already flickering with ethereal blue flames.

The flames were unusually quiet, yet they began to distort the surrounding air.

"With magic as the guide, and will as the fuel."

The moment the ethereal blue flames lunged towards the diary, the diary vibrated violently, emitting a piercing shriek.

Black ink seeped from the pages, attempting to form a twisted human face, but it quickly dissipated under the scorching of Fiendfyre.

"It's resisting," Lin Du observed calmly. "Trying to find a host."

"Tom was always overly confident," Dumbledore watched the burning Horcrux intently.

As Fiendfyre continued to burn, the diary gradually carbonized, and the shrieking finally turned into wisps of smoke.

When the last page turned to ash, the office fell into a peculiar silence.

"It's over," Lin Du put away his wand. "But this is definitely not the only one."

"I suspect there are seven," Dumbledore said. "Seven is a number with powerful magic, and Tom had a morbid fascination with Dark Magic. He must have had an extraordinary obsession with this number."

Lin Du mused, "So Voldemort will indeed return."

"His main soul is still wandering somewhere, waiting for the opportune moment to return," Dumbledore's voice was heavy. "What's more worrying is that his followers have never truly given up."

Outside the window, thunder exploded above the castle, and lightning illuminated the two figures' faces, flickering on and off.

"This is why I need your help, Lin Du," Dumbledore turned to face him. "When the last war broke out, you were too young, but now..."

Lin Du finished his sentence: "But now, I know too much and possess too much."

"Precisely," Dumbledore's blue eyes twinkled with wisdom behind his spectacles. "You not only command powerful magic, but more importantly, you understand how to maintain balance between power and conscience. This is exactly what we need most."

Lin Du walked to the window and looked at the swaying tree shadows in the Forbidden Forest in the distance.

"Interesting," he suddenly chuckled. "I've perused countless forbidden books, touched knowledge deemed taboo, all simply to see what boundaries 'life' could be pushed to by magic."

He turned, his gaze fixed directly on Dumbledore, the corners of his mouth still curved in that mocking smile.

"And now, the most pressing research topic is actually learning how to completely push back someone else who is trying to cross the boundary."

He shook his head. "Can this be considered a kind of... dark humor?"

Lin Du didn't wait for a response. He took a step forward, extending his hand to Dumbledore.

"So, isn't the answer obvious, Headmaster?" His tone was calm.

"Since this noseless gentleman insists on disturbing my research, I'll have to personally send him to a final, deep sleep."

He paused, a cold, faint glint flashing in his eyes.

"Tell me, Order of the Phoenix, are you still accepting members?"

Dumbledore gazed at him for a long time. The gentle lines on his aged face slowly relaxed, finally forming a deep, knowing smile.

"Of course," he said, taking Lin Du's hand. "The Order of the Phoenix will always open its doors to those willing to fight for the light."