"Emperor Wu banished the Hundred Schools of Thought and solely honored Confucianism. Without top-tier support, they could still go into hiding among the populace."

At this point, Yu Feibai argued forcefully: "For thousands of years, no matter how the imperial court forbade them, secret societies in the civilian sector haven't diminished; in fact, they've multiplied. Especially during times of unrest, never mind the Way of Peace or the White Lotus Society, groups like the Green Gang, Hung Mun, Ge Pao Hui, Small Knife Society, Qian Men, and so on, were spread across the entire nation."

"Even though these civilian organizations don't appear in official histories, that doesn't mean they never existed."

Saying this, Yu Feibai grinned slyly: "Even now, anyone who does carpentry likely pays homage to Lu Ban as their grand ancestor. How can you claim the Lu Ban School has vanished?"

"You're deliberately confusing the issue." Wang Guan found it both amusing and exasperating. "The people of the Lu Ban School and the Lu Ban School itself are not the same thing."

One was a trade guild, lacking formal organization, essentially a pile of loose sand. The other was strictly disciplined, akin to a modern corporation. The two simply could not be conflated.

Yu Feibai waved his hand dismissively, "Close enough, don't get bogged down in semantics."

Wang Guan was speechless but felt a flicker of curiosity, picking up the bronze plaque to examine it. At first glance, his impression matched Yu Feibai's: he doubted the object held any mechanisms. After all, the bronze plate was seamless, as if cast from a single piece of metal, and it felt quite heavy, seemingly solid. Logically, it shouldn't conceal any hidden workings.

However, Elder Hou had also mentioned that superior mechanism techniques were merely potent illusions—the more impossible something seemed, the more likely it was to be true. Solving a mechanism tested not just sharp eyes, but intellect as well. Wang Guan honestly admitted his intellect was average, but his eyesight was good. After scrutinizing it for a while, he focused on the five flying bats etched onto the plaque.

"Don't waste your effort." Seeing his focus, Yu Feibai kindly warned him. "I've already tried. No matter how I pressed, twisted, or pried, those bats wouldn't budge. They must be purely decorative, something meant to mislead you, with no tricks involved."

"Is that so?" Wang Guan tried pressing one. Indeed, the bat felt rigid, showing no sign of yielding. He tested every single one, still finding nothing. "It really is..." At this point, Wang Guan also frowned, setting the five bats aside for the moment.

He flipped the bronze plaque over to examine the swirling cloud pattern on the other side. The clouds were carved in intaglio, shallow etchings with crisp, fluid lines. Of course, these carvings might also conceal a mechanism, so he continuously ran his fingers over them, hoping to find some anomaly.

"Fumbling around is useless," Yu Feibai poured more cold water from beside him. "I scraped every line with my fingernail; absolutely nothing happened."

"That just means you didn't find the trick." Elder Qian chuckled wisely at this point. "Cracking the mechanism itself is simple; finding the key to it is likely the hard part."

"But not too hard," Elder Hou smiled broadly. He offered an incentive: "I have to return this afternoon. If you manage to solve the bronze plaque's mechanism without any hints before I leave, I'll take you for a tour of the research institute."

"Really?" Yu Feibai's eyes lit up instantly. He had been studying the plaque, but he had also occasionally paid attention to Elder Hou's discussions, knowing the institute housed many miraculous mechanisms. He was deeply curious about those objects and eager for a sneak peek.

"I'm an old man; I wouldn't lie to deceive you." Elder Hou chuckled, adding a caveat: "Pay attention, I said you solve it yourselves. You can't ask anyone else for help. Especially you, Ling Xi, you are not allowed to conspire with them to cheat!"

"Don't worry. I never interfere with their own endeavors," Elder Qian smiled, raising his cup. "Let them be busy with their puzzles; we'll continue drinking..."

"Exactly what I intended." Elder Hou took a sip of wine, sighing with appreciation. "The aftertaste is endless."

"Wang Guan, quick, quick..." Meanwhile, Yu Feibai urged him on. "Stop holding back; show us your true skills! A mere little bronze plaque certainly can't stump you. Hurry up and crack it, then we can go see more wondrous mechanisms together."

"Easier said than done," Wang Guan retorted wryly. "If it were so simple, why didn't you solve it yourself?"

"I haven't been in the right state these past couple of days. Otherwise, with my intelligence, I certainly wouldn't need you to step in." Yu Feibai shamelessly pushed back. "Alright, stop complaining. You should think of it this way: this is your chance to shine..."

"Quiet, I'm researching." Truthfully, not just Yu Feibai, but Wang Guan as well felt the pull of Elder Hou's offer. After all, as Elder Hou had explained, some sophisticated mechanisms and hidden weapons were too dangerous to be publicly disclosed, so they were kept in the institute solely for scholarly examination. Because of this situation, many amazing mechanisms remained unknown to the general public. Wang Guan, too, harbored a curiosity to visit. This was the innate human desire for knowledge, natural and undeniable.

However, the secret within this bronze plaque was truly difficult to unravel. Wang Guan pondered it for a long time. Finding no leads, he casually passed the plaque to the equally curious Fang Mingsheng, letting him exercise his mind for a bit. As for himself, he picked up food and focused on eating.

"What? You're giving up after only a few minutes of research?" At this moment, Yu Feibai chastised him with the tone of someone frustrated by wasted potential: "The last mile is the hardest. The late Emperor's venture was not even halfway complete before he perished mid-journey. To stand at the edge of a thousand-foot precipice only to fall short of the peak..."

"What does standing at the edge of a thousand-foot precipice have to do with falling short of the peak?" Wang Guan was intrigued.

"Of course there's a connection," Yu Feibai retorted impatiently. "It could have stood ten thousand feet tall, but because you gave up like this, it only reached a thousand feet!"

"You're something else," Wang Guan conceded, cupping his hands in mock admiration. "You can connect anything."

"Hmph," Yu Feibai sneered, clearly pleased with himself. "Child's play, nothing much."

"I wasn't trying to praise you..." Amidst the chatter, lunch concluded, and everyone returned to the living room for a brief respite. After some casual conversation, Elder Hou asked with a smile, "Well? Have you cracked the mechanism yet? Shall I tell you the answer?"

"Elder Hou, no rush," Yu Feibai held the plaque, contemplating while trying to persuade him. "Since you've made a rare trip to the capital, aren't you planning to stay and enjoy yourself for a few more days?"

"Due to work requirements, I spent nearly ten years in the capital; I'm quite tired of sightseeing," Elder Hou smiled faintly. "Besides, I took leave for this trip; I can't afford any delays."

Hearing this, Yu Feibai couldn't help but sigh with resignation. "In that case, please enlighten us, Elder. Otherwise, I won't sleep tonight."

"Wait..." Just then, Wang Guan stretched out his hand. "Give me the plaque."

"Huh?" Yu Feibai's spirits lifted instantly, his face showing delight. "You've figured out the method?"

"Let's see." As he spoke, Wang Guan took the plaque, his expression one of calm confidence. It was the final moment; after racking his brain fruitlessly, he didn't want to miss this opportunity, so he decided to cheat subtly. Anyone who gets an external advantage finds it hard not to feel confident.

Wang Guan was now sure of himself. He casually placed the plaque on the coffee table, and under the gaze of everyone present, he pressed down on four of the flying bats, leaving only the one in the lower right corner untouched. As Wang Guan pressed all four fingers down simultaneously, a faint click of a mechanism engaging could be heard upon careful listening. Those nearby also clearly saw the lower-right bat slightly jutting out.

"Damn it, it was the lower right one, not the center one?" It was no wonder Yu Feibai swore. He had pressed the bats himself earlier—corners, adjacent corners, even pressing the four cardinal points simultaneously—but nothing happened, which is why he assumed the five bats were purely decoration. Yet, he never imagined the movable part of the mechanism would be the lower-right bat, not the central one as he had supposed.

"Who told you it had to be the center bat?" Elder Hou's eyes were filled with approval, then he smiled. "Didn't I say it? The setup of a mechanism is, fundamentally, a way to fool the mind. The key lies in the word unexpected. With five bats, arranged orderly, four of them forming opposing pairs, most people would instinctively assume the central bat is the pivot point. A mechanism master will certainly go the opposite way. If you can't even consider that, then it's natural that you can't solve the mechanism."

"...Tricked again," Yu Feibai slapped his forehead, filled with regret. But he quickly composed himself and asked curiously, "By the way, Wang Guan, how did you determine it was the lower-right bat, and not one of the other corners?"

"Because compared to the other four bats, the surface of this one is shinier," Wang Guan explained casually, his finger then pressing and gently turning the lower-right bat by one hundred and eighty degrees. While the side with the bats showed no visible change after the rotation, the swirling cloud pattern on the opposite side quietly reconfigured itself, finally forming a character written in seal script.

"What character is that?" Yu Feibai squinted, hesitating. "It looks like the character 'Zu' ()?"

"Correct, it is the character Zu," Elder Hou confirmed without doubt.

"'Zu'?" Yu Feibai was astonished. "What does that mean? The ancestor of mechanism arts?"

"Don't talk nonsense." Elder Qian smiled and explained. "This is the 'Zu' from Zu Chongzhi, indicating that this mechanism door inherited its learning from Zu Chongzhi, who they consider their founding master, and claim discipleship under him."

"Zu Chongzhi? Wasn't he just a mathematician? How is he connected to the mechanism school?" Instantly, not only was Yu Feibai dumbfounded, but Wang Guan was also greatly surprised.

"Who told you Zu Chongzhi was only a mathematician?" Elder Qian frowned. "You haven't been reading your books carefully..."