December at Hogwarts seemed as if it had been struck by a Severing Charm. On one side were the increasingly lavish Christmas decorations in the Great Hall, the scent of gingerbread drifting through the corridors, and the students' excited discussions of holiday plans; on the other were conspiracies breeding in hidden corners, unseen by the light, and ever-escalating confrontations.
The anonymous warning letter was like a poisoned thorn lodged in Snape's heart. Beneath his outward gloom and calm roiled fury like volcanic lava, along with doubled vigilance. He no longer acted alone. Even in the Slytherin common room, he chose the most secluded corner, keeping his back to the wall to ensure no one could approach from behind.
The task of tracing the warning letter's source was mainly carried out by Lin Yanqing under the guidance of the System's [Trace the Source] mission. He spent a great deal of time in the library consulting books on magical inks and disguised handwriting, and cleverly questioned a first-year Gryffindor who managed the owlery. He learned that several dull-feathered Barn Owls, not part of the usual communication network, had indeed stopped at the owlery briefly recently.
"Ding-dong! (??????)?? Mission [Trace the Source] completion: 30%! The messenger has been confirmed as an outside barn owl. Partial reward issued: Tracking Dust x1 has been deposited into the System space."
The clues pointed beyond the school, or at least to someone who could use nonstandard owls. This temporarily ruled out the Marauders—they were more inclined to use direct methods such as school owls or the Marauder's Map.
Meanwhile, the second attempt at the Wolfsbane Potion began in a far more cautious atmosphere. Failure had been like a bucket of cold water, dousing some of Snape's impatience born from anger. He became exceptionally focused and rigorous. Every step was recalculated again and again, and every added ingredient was controlled to the most precise measurement. Lin Yanqing served as the most reliable brake and calibrator, sensing the flow of Snape's magic through their contract and, before a minute deviation could arise from excessive tension, handing him the required tool or suggesting an inspection at precisely the right moment.
It was a silent, highly coordinated dance, performed day after day in the laboratory beneath its ghostly green lights.
That evening, when a fresh batch of Silverleaf Grass base liquid finally stabilized and reached textbook-perfect quality, Snape did not immediately proceed to the next step. He walked to the shelf where the ingredients were stored and took out a small bundle from a locked dragonhide pouch.
Inside were several strands of thread gleaming with a soft moon-white luster, along with several Mithril Needles as fine as hairs yet extraordinarily tough.
"For you." He placed them on the workbench where Lin Yanqing usually worked. His movements were slightly stiff, and he looked elsewhere. "Embroidering basic protective magic runes should not be difficult for a Ravenclaw."
Lin Yanqing looked at the materials in surprise. Moonstone-spun thread and Mithril Needles were both precious, specialized magical sewing materials, commonly used to make high-level protective fabrics. He immediately understood Snape's intent—this was a response to his earlier creation of warning iron plates, a return based on the "principle of reciprocity," and also some... practical consideration for the personal safety of his "co-conspirator."
"Embroider the basic variant runes of the Shield Charm on the inside of your robes," Snape said in the same flat tone, as though assigning homework. "The effect will not compare to a real Shield Charm, but it can offset part of the force of a sudden attack. At least... if someone tries something underhanded, you will not immediately lose your ability to act."
He had not said, "Protect yourself." He had said, "You will not immediately lose your ability to act." That was very Snape-like—twisting concern into the maintenance of the team's combat effectiveness.
Lin Yanqing did not refuse. He picked up a strand of moonstone thread and felt the gentle yet steadfast protective magic contained within it against his fingertips. "Thank you," he said softly, then added, "Do you need me to embroider yours as well?"
Snape's body stiffened almost imperceptibly. Then he gave a cold snort. "No need. I have my own preparations." He was clearly unused to, and resistant toward, matters that were overly "intimate" and involved personal clothing.
Lin Yanqing did not press the matter and began studying the properties of the thread and needles. He discovered that steadily embroidering runes with magical effects onto soft fabric required immense concentration and a steady hand. It was no less difficult than handling certain delicate potion ingredients. This was undoubtedly another form of practice.
Over the following days, in the intervals between experiments, Lin Yanqing gained another activity—practicing magical embroidery. Snape occasionally cast a glance his way. When he saw Lin Yanqing clumsily trying to pass the first thread through the needle's eye, or saw the crooked runes he embroidered without the slightest magical fluctuation, he would let out an almost inaudible scoff, but he never offered instruction.
It was not until Lin Yanqing, distracted for a moment, let the tip of a Mithril Needle prick his fingertip and draw a tiny bead of blood that Snape finally frowned and impatiently tossed him a small bottle of transparent ointment.
"Diluted Comfrey Essence. Do not get blood on the materials."
Lin Yanqing caught the ointment and applied it to the tiny wound. The cool sensation instantly dispersed the sting. Looking at Snape's profile as he remained focused on the cauldron, the corner of Lin Yanqing's mouth curved slightly. He was beginning to grow accustomed to this awkward sort of concern.
Just as Lin Yanqing finally managed to embroider a small "Shock Absorption" rune with a stable structure that could faintly stir magical power, the System notification sounded again.
"Ding-dong! ヽ(??▽?)ノ Mission [Trace the Source] complete! It has been determined that the warning letter has an indirect connection to an owl network associated with the Borgin Family (Borgin). All rewards have been issued!"
The Borgin Family? Lin Yanqing's heart jolted. He knew that surname. It was connected to Borgin and Bork's shop in Knockturn Alley, representing Dark magic antiques and certain shady dealings. The warning letter was actually tied to Dark magic forces outside the school? Or was someone within Hogwarts connected to those forces and able to draw on their resources?
He told Snape of the discovery.
Snape's eyes instantly became razor-sharp, like a shark that had scented blood. "Bork..." he repeated the surname in a low voice. Understanding and deeper wariness flashed through his eyes. "It seems our 'friend' is hidden more deeply than we imagined, and is also more... dangerous."
He looked at the nearly completed Wolfsbane Potion on the workbench, glowing with a lustrous sheen, then at the newly formed and still immature protective rune in Lin Yanqing's hand.
"We need to be faster." His voice was low and urgent. "Before they take their next step."
In the corridor outside the laboratory, there seemed to be faint footsteps, but they quickly receded. The approaching Christmas holiday did not dispel the tense air surrounding the two of them. Instead, it made the sense of lurking danger clearer than ever.
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