HP: Those Years Sleeping with the Half-Blood Prince

"Thank you," Ian said solemnly.

Then Severus stepped forward and handed over a thin roll of parchment.

"Basic protection and identification against psychotic magic, focusing on the seventeen stealth forms of ancient heraldic variants."

Regulus took it, his fingers tightening. He didn't look at it immediately, but said in a low voice, "Slughorn might 'inadvertently' show a medieval alchemical manuscript at the next club gathering, which contains passages about the Philosopher's Stone."

"The book had been tampered with; several key pages were replaced, and the replacement content... pointed to an evil ritual that required a life sacrifice, with the aim of observing who would show unusual interest in the replaced content."

Ian and Severus exchanged a glance. It was another trap, targeting a young wizard with potential who might crave "immortality" and "power."

"We understand," Ian said.

The first meeting was very short.

As Ian left, he said to Regulus, "Next time... if you need it, the Room of Requirement."

After that, Regulus would occasionally appear at the Room of Requirement, always late at night, and for short periods of time.

He was usually very quiet, either reading the notes Severus had given him or staring blankly at some complex ancient runes.

Ian and Severus went about their own business, with Aris and Kevin also present. They tacitly refrained from asking Regulus what he was researching, only offering concise answers when he occasionally posed extremely technical and difficult questions, while Aris would provide supplementary theoretical background.

Kevin was a little reserved at first, but he soon realized that Regulus knew nothing about prank magic and Quidditch tactics, so he relaxed and would sometimes mutter, "What's so hard about this?" before being silenced by a glance from Aris.

Once, Regulus watched Severus skillfully handle a batch of moonflower roots and stems, and suddenly whispered, "My mother's old illness has relapsed, and the palliative medicine recommended by the healer at St. Mungo's requires an extract of mistletoe berries, but this year's quality..."

Severus didn't even look up: "I'll give you a stable extraction procedure another day."

Regulus paused, then said in a hoarse voice, "...Thank you."

On another occasion, Regulus told them something more urgent: someone was secretly collecting old cases of wizards being seriously injured in accidental attacks by magical creatures, seemingly trying to stage a few "accidents" that might target several Ministry of Magic employees and their families who had publicly called for vigilance against a resurgence of dark magic.

Ian, through family channels, subtly reminded his potentially involved father, John, to be careful and asked John to spread the warning to several trusted colleagues.

In return, when Regulus, pale-faced, mentioned in a meeting that the family hoped he would accompany the esteemed man to a gathering during Christmas where he might appear, Ian paused for a moment and said:

"Practice the Occupy Barrier technique until it becomes second nature. Also, prepare a potion that can make your magical fluctuations appear weak but stable for a short period of time. It might be useful in a critical moment. Severus can help you concoct it."

Severus nodded without asking any further questions and listed several materials, two of which were relatively rare. Ian noted them down, saying that he had some at home.

Regulus looked at the parchment, then at them, something slowly melting in his grey-blue eyes.

He opened his mouth, but in the end only said, "At the rally... I will try my best to remember who the people are, and... the tendencies of their conversations."

The exchange of messages and small acts of assistance took place in silence.

Trust is like a fragile layer of ice, gradually thickening beneath the dark surface of a lake.

During the Christmas holidays, Severus went to Ian's house as usual, and Regulus indeed went to the gathering. Upon his return, he sent a short message via encrypted note: "All is well. The list has been written down. The inclination is... more radical. Malfoy has been given more responsibilities."

The academy remained turbulent, but with Regulus as an inside man, many potential crises were silently resolved or avoided.

They remain cautious and avoid provoking others, but they are no longer blindfolded targets.

On a cold January night, the fireplace in the House of Requirement was burning warmly.

Kevin is playing chess with Aris and suffering his umpteenth crushing defeat; Severus is revising his thesis; and Ian is fiddling with a newly acquired pot of poisonous tentacles.

Regulus sat in an armchair a little distance from the fireplace, a thick book, "The Heraldry of Ancient Families," open on his lap, but his gaze was somewhat vacant.

After losing another game, Kevin sighed and leaned back, casually asking, "Regus, does your family really have to have twelve courses for Christmas dinner? I find it too much trouble for my mom to make six."

Regulus snapped out of his daze, paused for a moment, seemingly not expecting to be asked such a question.

He paused for a few seconds before saying, "...That's the tradition, but there were fewer people this year, so we only made eight dishes."

"That's a lot! What do you eat?"

"Goose, partridge, venison pie, meringue pudding..." Regulus rattled off a few dishes, his tone flat, but at least he was answering.

"That sounds too greasy," Kevin wrinkled his nose. "My mom's roast chicken and raisin pudding are much better."

"Kevin, taste is subjective, and we also need to consider the etiquette and symbolic meaning of traditional banquets..." Aris began to analyze rationally.

"Stop! Aris, I'm just complaining!" Kevin covered his ears.

Ian and Severus exchanged a glance. Regulus watched Kevin and Aris bicker, and the perpetually frozen coldness and emptiness on his face seemed to have cracked slightly, almost imperceptibly, by the heat from the fireplace.

After a while, Regulus suddenly whispered to Severus, "I tried the extraction procedure you gave me last time, and I succeeded on the third try. The potion is very stable, and my mother... is feeling better this week."

Severus grunted in agreement, his pen still nibbling: "The ratio of Moonfox feces to moonstone powder can be adjusted further for better results and fewer side effects. I'll give you the data next week."

"……good."

After sitting for a while, Regulus got up to leave. Reaching the door, he paused, didn't turn around, and said softly:

"Next week's Slughorn party, watch out for Nott's new friend, an exchange student from Durmstrang with a complicated background, and... thank you for the chessboard, though I'm not very good at it."

He was referring to the old chessboard that Kevin had forced on him last time to teach him the rules.

The door closed gently.

Kevin blinked. "Didn't he just say 'thank you'? And remind us?"

"Information points extracted correctly." Aris put away the chess pieces. "In addition, his chess skills do have a lot of room for improvement. Last time I gave him a handicap of queen and rook, and he still lost within twenty moves."

Ian smiled and looked at Severus, who also happened to look up at him.

The crackling of the fire was reflected in their eyes.