A lone rider broke through the thin frost before dawn.
Qin Feng had ridden hard through the night for two days, changing horses several times.
At last, the horse collapsed in exhaustion and dropped to its knees at the gates of Linbei City.
He merely stared upward in a daze, gazing at the city standing tall amid the wind and frost, and the silver-wolf banners fluttering atop its walls.
Twenty years.
Ever since that brutal battle in the Northern Frontier, Linbei City—once the Northern Frontier’s foremost military city—had become a dead city forgotten by the imperial court.
Yet now, what appeared before him still bore the ruins left by war.
But lamps had been lit along the city walls, and faint sounds of people could be heard from within.
This city, which the world had already sentenced to death, was actually in Xiao Yuan’s hands like withered wood meeting spring, slowly yet steadily beginning to pulse with life again.
Qin Feng took a deep breath, suppressing the shock surging through his heart, and strode into the city.
Today, he was here to attend an emergency military council that could change the entire Northern Frontier—and perhaps even the overall balance of Great Sheng.
◆◇◆◇◆
Linbei City, Northern Frontier Administration Office, secret chamber.
This was a highly classified military council of the highest level, yet deliberately kept extremely low-profile.
There were no ceremonial guards, no lengthy greetings. Everyone attended in plain clothes.
Xiao Yuan, the supreme commander of the Northern Frontier, sat at the head of the table, his expression as impassive as water.
Chief Administrator Xia Lanshi sat beside him, with thick files and blank sheets of paper laid out before him.
The covert-guard commander, Chi Banyue, casually toyed with the teacup in her hand, though sharp glints occasionally flashed through her eyes.
Qin Feng, the commander of Hanchuan who had just arrived, had not even removed his armor. He took his seat carrying the chill of wind and frost with him.
Pei Yi, the commander responsible for the defense of Linbei City, sat with a frown, his gaze repeatedly drifting toward the screen and then toward the newly appointed guest adviser.
Although that guest adviser appeared relaxed, Pei Yi could vaguely sense an oppressive aura from him. With just one glance, he could tell—
This was someone not to be trifled with.
As for the “Mr. Liuchu,” who was participating officially in the Northern Frontier’s highest military council for the first time as a guest adviser, he sat quietly to one side with his eyes lowered, seemingly completely out of place amid the surrounding atmosphere.
Behind Xiao Yuan, several screens had been arranged tightly together, and there was another person behind them.
That person was the rumored “Doctor Su.”
In the Northern Frontier, only a handful of people had seen Doctor Su’s true face.
Even Pei Yi, who was stationed in Linbei City, had never seen him. He did not know his real name, only that such a person existed.
But he understood clearly that this was a rule of the Northern Frontier military.
It was not because the people in the room were untrustworthy.
On the contrary, everyone sitting here today was a trusted confidant of Prince Su.
But classified information had different levels of access.
Clearly, Doctor Su’s true identity and real name had both been designated as the highest-level military secrets.
He knew very well that the fewer people who knew certain things, the longer those secrets would remain alive.
Behind the screen, “Doctor Su”—Su Mu Chen, the core technical provider for this military council—sat upright.
He had never imagined that one day he would personally participate in a military council that might overturn the course of history.
He could not help feeling somewhat nervous, but even more than that, he was excited.
He had always been quite interested in ancient history, and today, he actually had the rare opportunity to gather with these people.
There was a commander, generals, and even a military strategist.
It was just a pity that he was separated from them by a screen and could not see anything.
What surprised him was that Owl had somehow become a guest adviser of the administration office, participating under the alias Mr. Liuchu.
Although there were signs that Owl’s mental state had improved, he was still somewhat worried that these matters might place additional pressure on him.
But then he thought about it again. Perhaps having something to do would help divert his attention and give him a goal in life.
“Today, I have summoned all of you here for one purpose only.”
At the head of the table, Xiao Yuan looked stern as he swept his gaze across the room.
He spoke in a deep, resolute voice:
“Establish the Northern Frontier Light Network.”
Those words were like a thunderclap, officially announcing the beginning of this secret military council.
Candlelight flickered, illuminating the solemn faces around the room.
Xia Lanshi stood and distributed the detailed agenda to everyone.
Behind the screen, “Doctor Su” spoke first.
“—First, everyone must understand one thing. The Light Network is not a beacon tower in the traditional sense.”
It was the first time Pei Yi and Qin Feng had heard Doctor Su’s voice, and both were secretly startled.
They had always assumed Doctor Su must be an elder, at least someone of a certain age, to possess such extraordinary wisdom.
They had never expected his voice to sound so young.
Su Mu Chen paused, seemingly giving everyone time to digest his words.
“It is a system capable of transmitting complex intelligence continuously, day and night. Its purpose is not merely to issue warnings. It has five functions: one, transmit military intelligence in real time; two, rapidly report disasters; three, efficiently handle civil administration; four, coordinate the operation of commercial routes; and five, dispatch medical resources.”
At this point, Su Mu Chen’s voice rose slightly.
“Furthermore, if it can eventually be fully implemented, it will be capable, to a certain extent, of replacing the eight-hundred-li emergency courier system.”
The moment those words were spoken, the entire room fell into deathly silence.
Replacing the eight-hundred-li emergency courier system.
That meant the communication speed of the entire Great Sheng would undergo a earth-shaking transformation.
It meant distance would no longer be an obstacle. It meant the reach of governance could instantly extend to every corner.
Qin Feng sucked in a breath.
He finally understood why Xiao Yuan had summoned them here so secretly.
This was not merely a construction project.
It was a weapon capable of overturning the realm.
Su Mu Chen continued explaining.
“The operation of the Light Network is based on light reflection. Telescopes will be used to magnify the signal points, while observation posts must maintain line of sight according to the terrain. Each tower must be at least thirty chi in height.”
He paused, then pointed directly at the critical issue.
“Fog, blizzards, nighttime, and heavy rain are all enemies of the Light Network. We must acknowledge that the Light Network will not always be reliable, and contingency measures are necessary. The Light Network does not completely replace the existing system; it supplements it. Outside of extreme weather conditions, it will be the fastest and most effective method available on this land.”
Xia Lanshi then distributed military telescopes and sunlight signal mirrors to several people who had never handled them before.
He explained concisely, “When visibility is good, the telescope can see approximately thirty li away. The signal mirror can transmit coded signals using sunlight. At night, oil lamps will be used as the light source to send signals.”
Xia Lanshi spread a huge map of the Northern Frontier across the military council table and pointed at the red dots marked on it.
The red dots connected into a winding line, like a lifeline.
“For the first phase, we will build only one line.”
Xia Lanshi’s voice was steady and powerful.
“It will run from the Northern Watchpost to Linbei City and then to Hanchuan. Preliminary estimates indicate that this main line will require approximately twenty-six secret observation posts. The actual number will need to be fine-tuned after on-site surveying. Based on the current distances and the capabilities of the telescopes, the margin of error should not exceed three posts.”
He drew a line across the map, connecting the points.
“This is the first main line. Only after this entire line is completed and tested without errors will we extend it toward Linzhou, Cangzhou, Heguan, and the other prefectures and counties.”
Build a solid foundation, advance step by step, and secure every position before moving forward.
That had always been Xia Lanshi’s way of doing things.
Looking at the network covering half of the Northern Frontier, everyone’s expressions grew solemn.
They realized that this was a massive national defense project.
Pei Yi looked at the sunlight signal mirror in his hand, but the frown on his brow did not ease.
He raised his head and looked sharply toward the screen.
“Doctor Su, using this mirror during the day is naturally feasible. But what about at night?”
At those words, everyone’s expressions tightened slightly.
Pei Yi continued in a low voice, “The Northern Di are especially fond of launching night raids. If the enemy attacks the camp in the middle of the night, how do we transmit a message without sunlight? Military intelligence is as urgent as fire. We cannot possibly wait until dawn.”
This was the fatal blind spot that any general leading troops into battle would naturally consider first.
“That is why the Light Network has never meant a sunlight-only network.”
Su Mu Chen’s calm voice came from behind the screen.
“During the day, we use the sun. At night, we use oil lamps.”
He paused, then explained in detail.
“We will not simply wave lamps around in the darkness. Instead, specially designed focused oil lamps will be placed inside enclosed boxes. By opening and closing light-blocking panels, the beam will appear only in the required direction and at the required time.”
As he spoke, Xia Lanshi brought out a windproof focusing lamp model equipped with an opening-and-closing mechanism and placed it on the table for everyone to see.
With each opening and closing, the light and darkness alternated with precision.
Qin Feng looked at the model, still doubtful, and picked up the conversation.
“But an oil lamp can never match the brightness of sunlight. The Northern Frontier is vast. Can the signal really be seen in the darkness?”
“Not directly with the naked eye,” Su Mu Chen replied.
Xia Lanshi immediately added, “Each observation post will be approximately twenty li apart. We will not be looking directly from the Northern Watchpost to Linbei City. Instead, the signal will be relayed from one station to the next, with telescopes providing assistance. Even at night, these telescopes can detect the flashing signals of lamps thirty li away.”
After hearing Xia Lanshi’s explanation, the solemnity between Pei Yi’s brows did not completely disappear.
He was silent for a moment before suddenly lowering his voice.
“There is another matter I cannot put aside.”
Xiao Yuan slightly raised his eyes, signaling him to continue.
Pei Yi’s gaze swept across everyone in the room, as though confirming that there was no one who should not be present in the secret chamber.
Then he spoke.
“The thirty thousand troops Your Highness has in the Northern Frontier may nominally be under Your Highness’s command, but among them… there are people who do not answer to Your Highness.”
The moment he said this, the atmosphere in the military council room tightened abruptly.
Everyone knew that among the thirty thousand soldiers the emperor had assigned to the Northern Frontier, besides Xiao Yuan’s own personal guards and troops drawn from various parts of the Northern Frontier, there were also soldiers from the capital garrison.
These capital garrison troops were nominally “supporting” Prince Su, but in reality, they were there to monitor and restrain him.
Among them were spies belonging to the Crown Prince, other princes, and even Sheng Yuanli.
Xiao Yuan did not trust these people, but he could not openly remove them either. To this day, they remained stationed at the western military camp in Linbei City.
Pei Yi continued, “Once the observation posts are built, these people will inevitably notice them. The moment we finish building them, someone will write a secret memorial and send it back to the capital. If the emperor learns that the Northern Frontier possesses such an extraordinary technique…”
He did not finish.
But the rest of his sentence hung clearly in the air.
Xia Lanshi gave a faint smile and took out a sheet of paper, unfolding it flat on the table.
It was a topographical map of the area surrounding Linbei City, marked with several abandoned beacon towers, arrow towers, and old towers.
“I had already considered what General Pei mentioned.”
Xia Lanshi’s voice was unhurried as his fingertip lightly traced across the map.
“That is why the observation posts will absolutely not appear in the form of ‘newly constructed buildings.’”
He raised his pale-red eyes.
“City-defense arrow towers, frontier beacon towers, high towers beside military granaries. These are all structures that already exist in the Northern Frontier, so they will not attract attention. Every observation post will appear externally to be an old structure. Newly built observation towers will simply be constructed in the style of beacon towers or arrow towers, integrating them into the Northern Frontier’s existing military defense system. No one will notice anything unusual.”
Chi Banyue raised an eyebrow.
“What about the prefectural cities?”
“The prefectural cities are even more convenient.”
Xia Lanshi smiled slightly and moved his fingertip to the location marked “Linzhou” on the map.
“High towers at temples, bell towers at Taoist monasteries, tall buildings in the back courtyards of commercial houses, upper floors of teahouses. These places already see nobles and merchants coming and going, so ordinary people will not find them suspicious, nor will the authorities specifically inspect them. We only need to add an enclosed observation room inside, and it can serve as a concealed observation post.”
After hearing this, Pei Yi’s expression gradually relaxed.
“So even if those people really see them, they will only think they are ordinary beacon towers or arrow towers.”
“Exactly.”
Xia Lanshi slowly withdrew his finger, his tone calm and certain.
“Everything they see and hear will be exactly what they ‘should see.’ As for the system operating inside—if they are capable of noticing that, they would not have been sent to the Northern Frontier as spies in the first place.”
A few quiet laughs escaped from the seats.
Xiao Yuan did not laugh, but the coldness in his eyes eased slightly.
Qin Feng nodded, but then thought of the practical conditions among the lower ranks of the army and could not help asking another question.
“But what if the soldiers assigned to guard the posts fall asleep? If even one station fails to see the signal, wouldn’t the entire line be broken?”
This time, before Su Mu Chen could speak, Chi Banyue casually smiled and picked up the conversation.
“That is why one tower can never have only one person.”
Her fingertip lightly tapped the tabletop, but her tone carried the icy severity of military regulations.
“At least four people per tower, working day-and-night shifts, with two people on duty at a time. One person is responsible for observation, while the other handles recording and verification. Any mistake or omission will be dealt with under military law.”
“Now that the objective is clear, the next step is division of responsibilities.”
Xiao Yuan looked toward everyone.
Qin Feng was the first to speak.
“The Hanchuan defense line can dispatch its finest combat engineers to assist with construction of the observation posts.”
A ruthless glint flashed through his eyes.
“Military orders are absolute. Where the post stands, the men stand. If a post is attacked, destroy the mirrors and issue a warning. We will never allow this technology to fall into enemy hands.”
Pei Yi immediately spoke next, displaying the practical style of a soldier.
“With Linbei City as the starting point, I will personally oversee construction of the first observation post. A stone foundation, wooden upper structure, lightning protection and waterproofing. If supplies and manpower are available, the entire first-phase main line can be completed and connected within three months.”
He looked toward Xiao Yuan.
“This isn’t just building houses. It’s building a defense line.”
Xia Lanshi recorded everyone’s remarks.
“The Northern Frontier Administration Office will be responsible for recruiting the best craftsmen and ensuring construction progresses on schedule.”
“But even if we finish building it…”
Chi Banyue put away her smile, her tone turning sharp.
“What if the enemy discovers our light signals and deliberately lights lamps at night, or simply seizes one of the stations and impersonates our troops to send false orders?”
A series of questions struck directly at the Light Network’s weak points.
But Su Mu Chen seemed to have anticipated this.
“That is why every station must have a password that is updated every day.”
“A password?” everyone asked in confusion.
“That is, a code word. For example, today’s code word could be ‘White Tiger,’ and tomorrow’s could be ‘Azure Dragon.’”
Su Mu Chen explained, “Before sending official intelligence, the station must first transmit the code word for that day. Without the code word, or if the code word is incorrect, the receiving station will refuse to accept any message and immediately issue an alarm.”
This was essentially a dynamic verification-code system.
Chi Banyue nodded, finding the method quite good.
“The covert-guard camp will first select a group of people for training. In the future, this will become a skill that every covert guard must learn.”
Xia Lanshi spoke at this point.
“I will draft the first version of the ‘Light Network Regulations.’ After formal testing, we will continue making adjustments and updates.”
Just as everyone was arguing over the technical and security details, Owl, who had remained silent until then, suddenly spoke.
He did not look at the map. He merely calmly swept his gaze around the room.
“There is a problem.”
The entire room fell silent in an instant. Everyone’s eyes focused on the mysterious “Mr. Liuchu.”
Owl stood and walked over to Xia Lanshi’s side, his fingers tracing the red line on the map.
“What is truly expensive isn’t building the observation posts.”
Everyone looked puzzled.
Owl looked at Xia Lanshi and said word by word:
“What is truly expensive is maintenance. It is whether, twenty years from now, it can still continue operating.”
Owl withdrew his hand and calmly summarized:
“Building a system isn’t difficult. But keeping it running smoothly for twenty years—that is difficult.”
Upon hearing this, Su Mu Chen immediately realized that this was indeed a major problem.
He had only thought about establishing the system, while Owl had already considered the problem of long-term operation.
At present, the military telescopes and sunlight signal mirrors could only be obtained through Guichen Studio. Although these items had extremely long shelf lives and supplies could be stockpiled to ensure that the system continued operating for some time after the Gate closed, that was ultimately not a long-term solution.
Xia Lanshi’s eyes brightened slightly.
This was exactly what he had been searching for: administrative management thinking that went beyond mere engineering and construction.
“Mr. Liuchu is absolutely right.”
Xia Lanshi raised his eyes and asked, “May I ask what you suggest?”
Owl’s tone remained flat.
“As for the mirrors, in the future, Great Sheng’s craftsmanship may be able to produce something similar. But manufacturing telescopes will be very difficult. The lenses require specialized coating technology. Great Sheng will not be capable of achieving that even decades, or perhaps a century, from now. At most, it will only be able to produce inferior versions. And if production remains low, the cost will increase dramatically.”
Su Mu Chen was silent for a moment before letting out a soft sigh. His voice came from behind the screen.
“Mr. Liuchu has reminded me of something.”
Everyone held their breath and looked toward the screen.
“Indeed.”
Su Mu Chen’s tone was unusually serious.
“I cannot guarantee that telescopes and mirrors manufactured with these techniques can become a sustainable resource for the Northern Frontier.”
Those words fell like a heavy hammer, causing everyone present to sink into silence.
This was not merely a technical problem.
It was the Northern Frontier’s dependence on the Guichen Medical Sect.
Once the supply was cut off, this Light Network, which had consumed so much effort to build, would instantly collapse.