At the same time, Yu Feibai argued, "The textbook clearly records it this way: Zu Chongzhi was a person from the Southern and Northern Dynasties, a great mathematician who first calculated Pi to how many decimal places, and then nothing else was mentioned."

"It mentioned other things."

At this moment, Wang Guan struggled to recall, "It seemed to mention something else, perhaps related to a calendar."

"Yes, yes, yes..."

Yu Feibai nodded vigorously, "It seemed he compiled some kind of calendar that was decades ahead of the world, and to commemorate him, they even named a crater on the far side of the Moon after him."

"You only remember his achievements in mathematics and astronomical calendars, but you overlook that he was also an outstanding mechanical expert," Elder Qian shook his head and spoke slowly, "Zu Chongzhi was from the Southern Dynasties. His grandfather, Zu Chang, served as the Grand Artisan Minister of the Liu Song dynasty, overseeing civil and construction engineering, so one could say he had a profound family legacy in this area."

"Civil engineering absolutely involves mechanics, what the ancients called jiguan (mechanisms/devices). Zu Chongzhi was exposed to these things from childhood. Through constant immersion, he must have developed a strong interest, leading him to begin his research."

At this point, Elder Hou added from the side, "Even in his youth, he had a reputation for being learned and versatile. He was sent by the court to conduct research at what was then an academic research institution—the so-called Hualin Academy. Although he later served in external posts as an official or county magistrate, he continued his academic research and achieved great success."

"According to historical records, he created many ingenious machines, such as the South-Pointing Chariot, the Thousand-Li Boat, and the Water-Powered Trip Hammer."

While speaking, Elder Hou chuckled, "This is likely why some Jiguan Shi (Mechanists/Artificers) revered him and established the Zu School. Unfortunately, because this was a secret organization with highly concealed activities, there is no record of it in written history."

"If not for artifacts like bronze plaques discovered in some ancient tombs, we probably wouldn't even know this organization ever existed."

Elder Hou sighed, "But there are too few items—just scattered fragments. We know that it existed, but not why it existed. We have no understanding of the organization's rules, tenets, or doctrines."

"That's still good," Elder Qian comforted, "At least knowing such an organization existed is a start. Other things can be uncovered slowly. With patient research, the truth will eventually come to light."

"I hope so," Elder Hou said somewhat sadly, "But by then, I probably won't be around to see it."

No one knew how to respond to this. If they offered comfort directly, wouldn't that confirm Elder Hou's words? If they remained silent, it seemed inappropriate. It was indeed a dilemma.

Fortunately, this minor issue didn't stump Yu Feibai. He let out a hearty laugh and directly changed the subject: "Elder Hou, now that we’ve deciphered the mechanism on the bronze plaque, do your words still count?"

"They count, of course they count."

Elder Hou immediately laughed, "You can pack your bags now. You can leave shortly."

"We were just waiting for your word, Elder."

Yu Feibai didn't wait another second; he grabbed Wang Guan and headed off to pack. Fang Mingsheng, who was also keenly interested in mechanical artifacts, couldn't resist asking, "Elder Hou, could you possibly let me tag along too?"

"Certainly," Elder Hou agreed readily. Letting one sheep go or letting a flock graze made little difference; he didn't mind one extra person.

There’s little need to elaborate on what happened next. Everyone readied themselves. After bidding farewell to Elder Qian, they headed off in full force toward the airport, just in time to catch their scheduled flight.

"By the way, where exactly are we going?"

Only upon reaching the airport did Yu Feibai think to ask Elder Hou for the specific destination.

"First to Xianyang, then we'll transfer by road to Hanzhong," Elder Hou explained. "Hanzhong actually has an airport now, but it's still in the testing phase and hasn't officially opened yet. Otherwise, we could fly directly there."

"Hanzhong, what a great place," Yu Feibai nodded, immediately purchasing tickets, clearing security, and boarding the plane.

At this point, Elder Hou smiled and asked, "You say Hanzhong is great. What makes it great?"

"Uh..."

Yu Feibai was momentarily speechless. He racked his brain for a long time before finally sputtering out a single sentence: "It is the ancestral birthplace of the Han Dynasty; it must be excellent."

"That’s not entirely wrong," Elder Hou said with a smile. "The King of Han, Liu Bang, truly built an altar in Hanzhong to appoint Han Xin as his great general. He repaired the boardwalks in the open while secretly crossing the Chencang Pass, swept across the Central Plains, pacified the Three Qin states, and unified the world, establishing the Han Dynasty's reign of over four hundred years. Later, Liu Bei declared himself King of Hanzhong, and Zhuge Liang led six expeditions north from the Qishan Mountains, devoting himself completely until his final rest beneath Mount Dingjun..."

As Elder Hou spoke, the plane took off smoothly. About two hours later, it landed at Xianyang Airport.

Xianyang...

Stepping out of the airport, Wang Guan carefully observed his surroundings. The entire city was saturated with a modern atmosphere, looking no different from any other city in the country. Yet, for some inexplicable reason, he felt a slight heaviness in his heart, perhaps because of the profound history hanging over the area.

From the Qin Dynasty up until the Five Dynasties period, this region—the heartland of the Qin Chuan—was the center of the entire nation, the crucial battleground coveted by every lord. Whoever controlled this area possessed sufficient capital to challenge for the Central Plains and contend for supremacy over the realm.

Of course, even the finest region, having been fought over for a thousand years, suffered its damage. Thus, after the Song Dynasty, the nation's center began to shift—first south, then north—establishing the current configuration. However, that was the grand external environment. At least the city of Xianyang was developing quite well, with a thriving tourism industry, likely ranking among the best globally.

"Stop zoning out."

At that moment, Yu Feibai called out, "Let's go, time to transfer. What, have you never been to Xianyang before?"

"No, this is my first time."

"Oh, in that case, after we finish looking at the mechanisms, don't rush back immediately. Take a look around Xianyang first, and then we can go to Chang'an. Chang'an's antique market is bustling, and there are plenty of good finds," Yu Feibai said enthusiastically. "It would be a huge waste of this trip if we didn't pick up a few treasures to take home."

"That makes sense," Fang Mingsheng agreed wholeheartedly.

"There are many good things, but counterfeits are far more numerous. Be careful not to be duped," Elder Hou kindly reminded them. "Fake goods are rampant here; it's become a plague."

"We know that; it's the same everywhere," Yu Feibai replied dismissively. "We've been tested many times; we'll be careful. We won't be easily taken advantage of."

"That is true. You are disciples of Lingxi; you should possess some of his skill," Elder Hou smiled, then stopped speaking about it. He led the way, and soon they arrived at the train station.

After buying tickets and undergoing another transfer, they finally reached Hanzhong. However, it was already quite late by then. Following Elder Hou's direction, they went to his home, quickly ate dinner, digested their meal, and then retired for the night.

After a night of deep sleep, everyone was back to their energetic selves by the time they woke up the next morning.

"Elder Hou, can you take us now?"

After breakfast, Yu Feibai urged impatiently.

"Alright, we're leaving now." Elder Hou, with a warm smile, led the group out, got into the car heading towards the research institute, and seriously cautioned them, "Once inside, there aren't many strict rules, but there is one thing you must remember: no photography. Although it’s not a classified location, excessive publicity should be avoided..."

"Understood!"

Everyone nodded in unison, then watched as the car navigated twists and turns, finally arriving at an administrative compound. Wang Guan stepped out and saw that the sign hanging above the gate belonged to the local Cultural Bureau. The security was quite tight—there were not only wooden barriers to block vehicles but also a young security guard watching from the post.

Of course, with Elder Hou leading the way, Wang Guan and the others proceeded without any hindrance.

"Elder Hou..."

Along the way, they encountered several people, but these individuals were clearly either lower in rank than Elder Hou or showed him respect; consequently, they all paused to greet him. As for Elder Hou, he either offered a slight smile or a small nod; he was clearly used to it.

"We're here."

A few minutes later, Elder Hou led them to a corner of the compound—a courtyard-style building connected by two or three small structures. From the outside, it was lush with flowers and trees, giving the environment a very elegant tranquility.

In every respect, it looked like a perfect place for an elder like him to enjoy his retirement, completely different from the crisis-ridden, trap-filled research institute the group had imagined.

"Brother Hou, you’re back so soon?"

At that moment, an old man poked his head out from the courtyard and chuckled, "Since you took leave, you should rest a few more days! No need to rush back to work."

"I can't sit still," Elder Hou shook his head. "I'm due to retire next year. Then I can rest as much as I like."

"I doubt that," the other man laughed. "It seems like every year since five years ago, you've submitted your application to officially retire, but the higher-ups never approve it, strongly urging you to stay. Next year will surely be no different. Unless you’re resolute enough to truly walk away, your role as the Chief Consultant will continue."

Hearing this, Wang Guan had a sudden realization. He had been wondering why Elder Hou was still working at his age; it turned out he held the title of Consultant.

"Besides," the man added, asking a final question directed at Elder Hou, "If they really let you stop, would you want to?"

This made Elder Hou smile without answering. There was no way to reply, as researching the science of mechanisms was not just his job but his passion. If he truly grew tired of it and didn't want to continue, could anyone possibly force him? Ultimately, Elder Hou wanted to continue his research, and when the institute requested his continued service, he readily agreed.

"See? Was I right?"

The man teased him, then looked towards Wang Guan and the others, a hint of curiosity in his eyes, "Brother Hou, who are these?"

"They are junior acquaintances of Lingxi, interested in mechanical devices and hidden weaponry, so they wanted to take a look," Elder Hou explained with a smile. Given his status, bringing a few people along for a visit likely wouldn't meet any resistance.

Indeed, the man just nodded slightly and asked no further questions.

"Brother Pan, I'll take them in now," Elder Hou said, beckoning them over, and led Wang Guan and the group into the research institute—a place far different from what they had envisioned...