In the second week of December, Hogwarts was shrouded in the bustle of the holidays. Students discussed their plans for the christmas holiday, while the scent of gingerbread and roasted chestnuts drifted through the corridors. Yet beneath all that noise, discordant undercurrents stirred in certain corners.
Transfiguration Class had just ended, and the students filed out. As Lin Yanqing packed up his books, he suddenly felt a light tug on his sleeve. Looking up, he saw that Snape had already reached the classroom door and was giving him a swift glance over his shoulder—a signal to go to the Room of Requirement.
When Lin Yanqing arrived, he found Snape standing before the worktable, his expression even gloomier than usual. He held a crumpled piece of parchment in his hand, covered in slanted handwriting that had obviously been disguised:
"Curiosity killed the cat, especially on the night of a full moon. Some people would do well to learn to keep their eyes to themselves, or next time, they may lose more than a tuft of hair."
There was no signature, no wax seal. It looked as though it had been casually torn from some old book.
"It appeared in my Potions class textbook this morning." Snape's voice was icy as he tossed the note onto the table. "During the few minutes I left my seat to hand in an essay."
Lin Yanqing picked up the note and examined it carefully. This was not the Marauders' style. They preferred direct humiliation or pranks, not this sort of sinister warning. This felt more like... a genuine threat.
"You think it was the person outside the door that night?" Lin Yanqing asked.
"Obviously." Snape's fingertips tapped unconsciously against the tabletop, betraying his unease. "They know more than we imagined. The full moon, eyes..." He gave a cold laugh. "They are warning me not to continue investigating Lupin."
Ding-dong! (｀Д′)!! A clear threat against the contract target has been detected! Crisis Response Mission—[Trace the Source] has been triggered! Mission Description: The appearance of an anonymous warning letter means hostility has surfaced! Find the letter's origin or identify its sender. Mission Requirement: Determine the general identity of the warning letter's source or sender within 48 hours. Mission Reward: Tracking Dust (can adhere to a messenger or contact and provide short-term location clues) x1, System Points +80. Failure Penalty: The probability of the contract target encountering prank-level harassment increases by 50%. (▼へ▼メ)
"We need to find out who it was." Lin Yanqing set down the note and looked at Snape. "The handwriting was disguised, but the method of delivery is a clue. Whoever put it into your textbook without you noticing..."
"Was most likely in that classroom, or had an accomplice," Snape continued, a flash of malice passing through his eyes. "Someone watching me, and someone who does not want me looking too deeply into the secret of the werewolf."
That realization made the atmosphere in the laboratory even heavier. The enemy was no longer hidden behind a veil of mist. It had become a tangible, malicious tentacle reaching right before them.
However, misfortunes never came alone.
That evening, as they continued refining the Wolfsbane Potion, an accident occurred. Just as Snape prepared to pour the processed Moonlight Moss extract into the main cauldron for its crucial fusion with the earlier Silverleaf Grass base, Lin Yanqing suddenly sensed through their contract an extremely subtle hitch in the flow of Snape's magic—perhaps the strain of recent days and the sudden warning letter had distracted him.
That nearly imperceptible mistake caused the extract to drip in one hundredth of a second too fast.
Hiss—
The emerald potion that had been steadily swirling in the cauldron suddenly churned violently. Its color instantly turned cloudy, and it gave off a bitter, scorched smell. Unstable magical ripples spilled from the cauldron.
"Back!" Snape growled, swiftly flicking his wand in an attempt to stabilize the potion. Lin Yanqing immediately stepped forward as well, ready to cast a Stabilizing Charm.
But it was already too late. With a dull thud, the potion in the cauldron completely lost its balance, turning into a sticky mass of bubbling dark-brown sludge. Every medicinal property had been utterly destroyed.
Nearly two weeks of effort had been wasted just when they were about to see their first results.
A deathly silence filled the laboratory. Only the failed potion at the bottom of the cauldron let out faint, mocking gurgles.
Snape stood motionless. The knuckles gripping his wand had turned white, and the veins on the back of his hand stood out faintly. Through their contract, Lin Yanqing could feel the violent emotions that nearly consumed him—a mixture of frustration, rage, and self-loathing. He stared fixedly at the lump of waste, a storm roiling in his black eyes.
This was not merely a failed experiment. With an external threat closing in, it was naked proof of his own lack of strength. In the field he took the greatest pride in, he had suffered a crushing blow because of his own mistake.
Lin Yanqing did not try to comfort him. He knew any words would have been pale and useless at this moment. He simply walked forward in silence and began clearing the wrecked worktable, moving the ruined cauldron aside and preparing fresh equipment.
A long time passed—so long that Lin Yanqing thought Snape might remain frozen there forever—before he heard a faint voice, almost forced out through clenched teeth:
"...It was my mistake."
It was not an apology, but an admission born of hatred for his own incompetence.
Lin Yanqing paused and looked at him. Snape still did not turn around, but the taut line of his jaw showed how desperately he was controlling his emotions.
"We still have materials." Lin Yanqing stated the fact calmly. There was neither blame nor pity in his voice, as though he were merely saying that tomorrow would be sunny. "We can start over. Besides, we now know that when adding the Moonlight Moss extract, the speed must be slower than expected and the magical output more stable. This failure has prevented a possible collapse at a more crucial stage in the future."
He defined this failure as "valuable data."
Snape abruptly turned to look at him, disbelief in his eyes. He had expected disappointment, or worse, sympathy. Yet all he saw in Lin Yanqing's eyes was pure calm and an analysis of the facts.
The self-loathing that had nearly crushed him was strangely eased by those words. Failure was no longer pure shame; it was experience that could be analyzed and used.
He took a deep breath, then slowly let it out. The burning rage in his chest gradually subsided, transforming into a deeper, colder resolve. He no longer looked at the failed cauldron and instead turned toward the shelves holding their materials.
"Start over," he said hoarsely. His tone had regained its usual cold hardness, but something more settled had been added to it. "Next time, it will not fail."
Outside the window, the night was deep. Somewhere in the castle, the enemy who had sent the warning letter remained hidden. Within the laboratory, the shadow of failure had not yet fully dispersed. But the two boys—one clearing the ruins, the other preparing new materials—silently reached an understanding—
Threats would not make them retreat, and failure would not break them.
The real contest had only just begun.
Before you continue