Halloween Eve and the Dim Light of the Darkroom

In the last week of October, Hogwarts was shrouded in an atmosphere of restless agitation. The decorations for Halloween Eve began to appear, and the sweet scent of pumpkin pie wafted through the castle. But beneath this facade, several undercurrents collided with even greater intensity.

The Marauders' revenge came faster and more insidiously than expected. They no longer resorted to public insults or pranks that left obvious evidence. Instead, they turned to more vexing, persistent harassment—deliberately bumping into Snape and knocking books from his hands as he passed, only to apologize immediately; discussing certain people's peculiar habits in a not-too-quiet voice near him while he was engrossed in research in the library; and even subtly interfering with his potion-making with extremely faint magic power from an unknown source, always stopping just short of being traceable.

These actions were like the buzzing of flies and mosquitoes, incapable of causing substantial harm, yet endlessly testing Snape's nerves. Lin Yanqing could clearly feel, through their Contract, the growing, forcibly suppressed ferocity within him, like a volcano on the verge of eruption. However, Snape's response had also become colder and more efficient. He seemed to completely disregard the harassment, dedicating all his energy to two things: first, completing all his coursework with near-perfect performance, especially Potions class, using his impeccable grades as the most resounding slap in the face; second, immersing himself wholeheartedly in the dangerous and complex research to improve the Wolfsbane Potion.

This research required a significant amount of private time and an absolutely undisturbed environment. Clearly, the common room and ordinary empty classrooms were insufficient.

Three days before Halloween, after Potions class, students began to leave. Lin Yanqing deliberately slowed his pace while packing up, lingering at the back. Snape had already tidied his things but, instead of leaving immediately as usual, stood by his workstation, repeatedly polishing a small silver knife that was already gleaming.

When only the two of them remained in the classroom, Snape stopped his pointless action. Without looking at Lin Yanqing, his gaze fixed on a cabinet in the corner where discarded equipment was piled. His voice, low and almost inaudible, said:

"On the seventh floor of the castle, opposite the tapestry of Barnaby being clubbed by a troll. I need a... completely soundproof laboratory."

Lin Yanqing's heart stirred. The Room of Requirement. Snape knew about this place, and now, he had decided to use it as their secret research base. He was no longer just researching alone; he was formally inviting Lin Yanqing into his core research field.

"Understood," Lin Yanqing replied in an equally low voice, without further questions.

Snape gave a barely perceptible nod and was the first to leave the classroom.

That night, when the world was deep in slumber, Lin Yanqing went to the tapestry on the eighth floor and silently thought, "I need a potions laboratory." When a smooth door appeared, he pushed it open and entered.

The space beyond the door was slightly different from what he had imagined. It wasn't a spacious, brightly lit laboratory but rather a modified, somewhat cramped medieval alchemist's workshop. The walls were rough stone, and shelves filled with various bizarre glass vessels and metal instruments lined the walls. In the center of the room was a massive stone workbench covered in carvings and unknown stains. Several magic lamps hanging from the ceiling cast a faint green glow, illuminating the entire room like some kind of underground cave. The air was thick with a strong smell, a mixture of sulfur, dried herbs, and a certain metallic tang.

Snape was already there. He stood before the workbench, adjusting a complex miniature distillation apparatus made of crystal tubes and silver coils. The dim green light outlined his focused, cold profile.

He did not welcome Lin Yanqing's arrival, nor did he even look up. With a voice barely above a whisper, he rapidly and clearly listed a string of ingredients and their processing requirements, as if Lin Yanqing were merely an extension of himself, a naturally expected assistant.

"Moonstone powder, needs to be ground under moonlight until reflective. Drowsy Bean juice, extract at a temperature not exceeding forty degrees. And..." He paused, his voice dropping even lower, "...three strands of werewolf hair, must be from one shed voluntarily on the night of the full moon, cut with a silver dagger."

Lin Yanqing silently took note, not asking where he obtained these rare, even dangerous, materials. He began searching the shelves for the necessary glassware and reserve ingredients. For a time, the only sounds in the workshop were the faint hum of the instruments, the rustling of materials being processed, and the cold stream of thoughts transmitted through their Contract, concerning step verification and risk warnings.

They worked like two researchers who had collaborated for years, in the dim light, silently and efficiently. Snape was responsible for the core structure and magic guidance, while Lin Yanqing handled precise auxiliary operations and material pre-processing. The process was fraught with risk. Once, when adding a highly active catalyst, the magic in the crucible nearly went out of control. It was Lin Yanqing, sensing Snape's extreme pressure through their Contract half a second in advance, who promptly handed him the pre-prepared stabilizer, narrowly averting a small magical explosion.

After the crisis, Snape said nothing. He merely glanced at Lin Yanqing, his gaze akin to that of a craftsman looking at a crucial tool that hadn't failed him at a critical moment. Then, he returned to his work.

It wasn't until the sky outside began to whiten that the preliminary material processing and basic solution preparation concluded. Snape carefully sealed several vials of semi-finished potion liquids that shimmered with an ominous glow and hid them in a secret compartment beneath the workbench.

"That's enough," he said, his voice hoarse with fatigue. "Complete the initial fusion before the next full moon."

Lin Yanqing also felt mentally exhausted. This kind of high-intensity, risk-filled collaborative work consumed a great deal of energy.

The two left the Room of Requirement one after the other, in silence. The corridor was deserted, and the chill of early morning hit them.

At the fork leading to their respective houses, Snape stopped. His back to Lin Yanqing, he remained silent for a few seconds, then tossed something backward over his shoulder, tracing a slight arc.

Lin Yanqing instinctively caught it. It was a small amulet made of black dragon hide, with an ancient design. Intricate protective runes were carved into it, and a piece of obsidian that emitted a faint coldness was set in the center. The touch was icy, and it contained no small amount of protective magic.

"Wear it," Snape's voice remained devoid of emotion. "When you handle the wolfsbane moss next time, its spores will cause mental erosion."

He finished speaking and, without waiting for a response, quickly disappeared down the stairs leading to the dungeons.

Lin Yanqing stood in the empty corridor, holding the amulet that still carried a faint warmth from Snape's fingertips.

This was not a thank you, nor a return gift.

This was necessary equipment replenishment for a co-conspirator. It was pre-emptive protection against known risks in future work. In this cold manner, he confirmed Lin Yanqing's indispensable position in this dangerous plan and took on the responsibility of providing corresponding safety measures as the project leader.

The pre-Halloween morning light filtered through the stained-glass windows of the corridor, casting mottled shadows. Lin Yanqing put on the amulet, its cold touch pressing against his skin.

He knew that the territory they were venturing into was becoming increasingly dangerous. But the bond connecting them was also becoming stronger and... more complex, through this shared adventure and cold concern.

Hogwarts' Halloween was approaching, and for them, the real night of fright might have just begun.