Inside the main residence’s study, the doors and windows were tightly shut, and hidden guards had long since been stationed all around, cutting off every attempt to eavesdrop from the outside.
On the long table, a detailed complete map of the Northern Frontier was spread out flat.
On the parchment scroll, the ink lines of mountains, rivers, and passes crisscrossed one another, the ink somewhat faded with age.
It was an old map left behind twenty-five years ago, before Great Sheng had yet lost the territories of the Northern Frontier.
Xiao Yuan and Xia Lan Shi had already looked at this map hundreds and thousands of times. Every ravine and gully was deeply carved into their minds.
Xiao Yuan sat at the head seat, with Su Mu Chen sitting beside him.
Xia Lan Shi, Xiao, Chi Banyue, and Pei Yi took their seats in succession.
This was the first time Pei Yi had truly stepped into this core circle.
He sat upright, his expression solemn, yet he discovered that although these people all looked grave, not a single one of them showed despair or panic.
Xiao Yuan did not immediately begin discussing any strategy.
He merely took the bright-yellow imperial edict and calmly tossed it onto one corner of the long table with a slap.
“Starting today.”
Xiao Yuan’s gaze slowly swept across everyone, his voice low, yet carrying an unquestionable force:
“Everyone must be clear about one thing. This is not a battle to reclaim lost territory.”
“It is a dead end in which the Emperor hopes we will lose.”
The atmosphere in the entire study instantly sank, like a huge stone crashing into a deep pool. No one harbored even the slightest illusion anymore.
That sentence had set the tone: do not expect even a single grain of rice or a single soldier’s worth of support from the capital.
They could only rely on themselves to accomplish this impossible military order.
Xiao Yuan’s brows and eyes were even more solemn.
The “three months” written on the imperial edict was like a guillotine suspended above his neck.
He had no choice but to fight this battle.
He did not allow the heavy atmosphere to spread. His gaze swept across everyone, his voice low and clear. “The three lost territories we need to reclaim have already been lost for a full twenty-five years. Most of the old map in our hands can no longer be trusted.”
For the fifth Northern Frontier campaign, Xiao Yuan had long ago ordered people to redraw the map of the Northern Frontier.
However, having lost the territory, they could not go deep inside to verify it. They had never truly seen its situation clearly.
He braced both hands against the table and pointed directly at the core issue.
“So the first step of today’s military council is not tactics. First, we correct our intelligence—how much do we actually know right now? How much do we not know? And how much are we still missing?”
This sentence determined today’s topic.
Xia Lan Shi stepped forward and spread a newly drawn map over the old one.
It was a map filled with a sense of fragmentation.
Black ink lines outlined the terrain from twenty-five years ago.
The red lines were traces that scouts had brought back with their blood over the past three months.
And the large stretches of blank space were unknown restricted zones.
The lamplight illuminated the enormous map at the center of the table.
“Twenty-five years ago, when the Northern Frontier fell, there were only three military strongholds here.”
Xia Lan Shi pointed toward the northern side of the map. “According to the military reports from that time, Whitewater Pass was the northernmost pass of the Northern Frontier, Broken Cloud Fort was a small border fortress, and Wild Goose Rest Ferry was a seasonal crossing on the southern side.”
He paused for a moment, his fingertip moving downward along the ink lines of the old map.
“But twenty-five years is enough time for a city to change its name three times.”
“It is also enough for a river to change course, for an official road to be swallowed by weeds, and for another new road to grow elsewhere.”
“It is even enough for the people born there to have no idea that this land once belonged to someone else.”
He raised his thin, pale-red brows and spoke in a cool tone:
“So this map can only prove that they once existed.”
Chi Banyue lowered her eyes and continued, “We have confirmed that the three old sites still exist, but not a single one is still the same as it was twenty-five years ago.”
She took the opportunity to push forward a stack of secret letters and hand-drawn sketches, her voice cold and precise.
“Over the past three months, the Hidden Guard Camp and Listening Snow Pavilion have sent back a total of thirteen intelligence reports. Four came from passing merchant caravans, three from border herders, three from scouts, two from inside the Northern Di, and one from a Northern Frontier refugee.”
“Among this intelligence, several pieces have already been corroborated by two or three different sources, so their reliability is relatively high. But the portions involving the enemy army’s internal deployment still come from only a single source.”
Chi Banyue pointed at the three locations on the map and broke down the current situation described by these thirteen pieces of intelligence for everyone.
“Whitewater Pass has now been rebuilt by the Northern Di. Both merchants and herders have mentioned that there seems to be an additional outer barbican surrounding the pass. Some people have even seen a mountain path between the cliffs that does not appear on the old map.”
“Broken Cloud Fort is said to have been developed into the enemy army’s supply heart. Scouts observed from a distance that there seemed to be large grain warehouses inside the fort. A small settlement has even formed around it. Rumor has it that the grain stored there is enough to feed the enemy army for three months.”
“As for Wild Goose Rest Ferry, merchants reported that the Northern Di had built three iron-chain pontoon bridges there and constructed arrow towers along the banks. Heavy warships have been moored on the river year-round, completely blockading the waterway.”
Everyone present immediately understood.
What they were facing was not three isolated strongholds, but a genuine war system that the Northern Di had solidly developed over twenty-five years.
Xia Lan Shi immediately picked up his brush and rapidly filled in the terrain and enemy defensive lines on the parchment scroll.
Without raising his head, he continued, “The remaining intelligence from single sources, as well as the large areas of blank space on the map, are the blind spots we know nothing about.”
His brush drew a tightly connected dotted line between Whitewater Pass, Broken Cloud Fort, and Wild Goose Rest Ferry. Xia Lan Shi’s gaze was cold.
“Based on the current intelligence, Whitewater Pass is the ‘shield,’ responsible for resisting enemies; Broken Cloud Fort is the ‘heart,’ responsible for supplying blood; Wild Goose Rest Ferry is the ‘vein,’ responsible for transportation. The three form mutual support, so touching one part will affect the entire system.”
Pei Yi, who had been holding his breath in concentration, looked at the map after the corrections had been made. After pondering for a moment, he spoke up with his practical experience as a local commander.
“This new mountain path Changshi Xia marked—I saw it from a distance when I led troops on border patrol last year. That valley is extremely prone to accumulating snow and freezing in winter. Cavalry that goes up there will simply become sitting ducks once they slip and fall.”
He pointed toward the northwest side of Broken Cloud Fort. “And this narrow valley is prone to landslides once the spring thaw begins. If we advance this month, we will very likely encounter melting snow. It will be extremely difficult for a large army to circle around from there.”
Pei Yi’s experience gave the deductions on the paper an additional layer of cruel reality and time pressure.
Xiao remained silent.
He quietly listened to every detail, his gaze fixed on the map.
Although he remembered those “pasts” buried within time, every cycle contained many different details.
Every time the Door reopened, the world was already no longer the original world.
The current Northern Frontier was not entirely the Northern Frontier he remembered.
He was not certain which of the memories in his mind he should trust.
After all the fragmented intelligence had been pieced together like a puzzle on the map, forming a rough outline, the room fell into a brief silence.
Xiao Yuan braced both hands against the edge of the table. His gaze scraped inch by inch across the mottled map like a blade as he broke the silence in a deep voice:
“Then what exactly do we know now?”
Xia Lan Shi stepped forward, his fingertip hovering over the map. His tone was cool and certain, as though announcing a verdict.
“The three former military strongholds still exist.”
“The defensive scale of two of them has already expanded outward.”
“The river course at Wild Goose Rest Ferry has changed once.”
“And we also know that over these twenty-five years, the Northern Di rebuilt some of the roads convenient for moving troops.”
Having said this, his fingertip stopped over those large areas of “white.” His eyes suddenly darkened.
“But we do not know their actual troop deployment or the true strength of their defenses.”
Chi Banyue raised her eyes and immediately added, her voice soft yet grave:
“We know even less about how these three cities communicate with one another once hostilities begin, or who is coordinating them from the center.”
Xiao Yuan did not immediately respond.
He gazed for a long time at the unknown regions still shrouded in mist on the map. A dark killing intent surged within his deep eyes, yet it was suppressed firmly beneath an extreme calm.
After a long while, he slowly straightened and swept his gaze over everyone, delivering his conclusion one word at a time:
“So we still cannot determine which city to attack first.”
Just as everyone sank into thought, Xiao, who had been sitting quietly in the corner, finally spoke.
Xiao slightly lifted his eyelids, his indifferent gaze sweeping across the thirteen intelligence reports on the table as he calmly threw out a sentence:
“What if someone deliberately wants us to know certain things among these thirteen intelligence reports?”
The brush in Xia Lan Shi’s hand abruptly stopped, and his expression changed drastically.
He understood what Xiao truly meant.
The thirteen intelligence reports corroborating one another could, at most, prove that they matched each other.
They could not prove that they were true.
The Northern Di had been developing for twenty-five years. It was impossible that they had no awareness whatsoever of an enemy nation redeploying its troops.
Among these thirteen intelligence reports, there was a very high possibility that bait deliberately leaked by the enemy was hidden within them.
The most dangerous intelligence was often not false intelligence, but thirteen reports that corroborated one another—the “truth” that the enemy wanted you to know.
Xia Lan Shi said in a low voice, “If that is the case, then we must use another completely different source of intelligence to cross-check it.”
Xiao Yuan braced both hands against the edge of the long table, his eyes deep as night, filled with incomparable decisiveness.
“So, we absolutely cannot fight according to this intelligence.”
This was a military council without a conclusion, yet it was the most important decision Xiao Yuan had made since arriving at the Northern Frontier.
He looked at those areas marked “unknown.” Hidden there was the killing intent of tens of thousands of enemy troops, as well as Great Sheng’s chance at survival.
“Three days.”
“I want to know exactly who is obeying whose orders between Whitewater Pass, Broken Cloud Fort, and Wild Goose Rest Ferry; where the soldiers come from, where the grain goes, and how quickly reinforcements can arrive.”
He paused for a moment, his gaze blazing.
“As for exactly how many soldiers, how much grain, and how many crossbows and arrows are in the cities… there is no need to find everything out at once.”
“What I want is enough information for us to know where we can strike and where we cannot.”
“This is the intelligence gap we have right now. Until then, we will not discuss attacking the cities.”
Xiao Yuan stood before that incomplete map, as though engaging in a silent contest with the invisible enemy army hidden within that blank wilderness.
He knew that once he made his move, “that man” would also appear.
This was a fight to the death, so he had to make every preparation possible.
“Since that is the case, let us first see how many chips we still have in our hands.” Xiao Yuan looked at Pei Yi. “Pei Yi, military strength.”
Pei Yi immediately straightened his back. After all, he was the commander defending Linbei City and knew these figures by heart.
“Reporting to Your Highness, the existing troops that can be directly deployed: the Northern Frontier Army totals thirty thousand, including eight thousand capital troops. But those eight thousand capital troops absolutely cannot be trusted. We even have to guard against them defecting. After deducting the four thousand troops required for daily defense and those who must remain stationed here…”
Pei Yi took a deep breath and said heavily, “We truly have only eighteen thousand men who can immediately be mobilized for an expedition.”
He paused and continued reporting the cruel reality:
“Three thousand warhorses. Although bows, crossbows, and arrows were replenished not long ago, they cannot withstand prolonged consumption. Siege equipment is severely lacking.”
Finally, Pei Yi gave his judgment as a commander:
“If the enemy holds their defenses and refuses to come out, eighteen thousand men would not even be enough to fill the gaps between their teeth. To take all three cities within three months… is even more impossible.”
That sentence directly placed the cruel military reality before everyone’s eyes.
They were vastly outnumbered and desperately short of resources.
Let alone attacking a city—even if the Northern Di committed all its strength to launch an assault, defending the city would be difficult.
“Wait.”
A clear yet exceptionally calm voice abruptly interrupted Pei Yi.
Everyone turned their heads and saw Su Mu Chen slightly furrow his brows as he looked at Pei Yi and asked an extremely practical question that no military commander would consider first.
“If we absolutely have to fight,” Su Mu Chen’s voice was calm, yet carried the physician’s absolute composure, “then I want to ask one thing first. General Pei, if eighteen thousand men launch a forced assault, on average, how many wounded soldiers would there be in one day?”
Pei Yi froze for a moment.
When military commanders discussed matters, they calculated grain and soldiers. Very few people would begin by calculating casualties.
“Without an actual battle, it is difficult to estimate.” Pei Yi was silent for a moment before answering based on experience. “But if it is a frontal siege, several hundred casualties in a day would not be an exaggeration. If we encounter the defenders’ powerful crossbows, rolling logs, and fire oil, there could be even more.”
“Then use three hundred as the figure.”
Su Mu Chen lowered his eyes. The calculation mechanisms belonging to modern medicine and logistics instantly activated in his mind.
“Three hundred people. Three months means twenty-seven thousand casualty cases. This means we will need enormous quantities of clean bandages, alcohol, and large amounts of medicine. Besides that, to prevent the wounded camp from triggering an epidemic, we will also need large quantities of salt and clean water, as well as enough tents to isolate the lightly and seriously wounded.”
Su Mu Chen raised his head, his sharp gaze sweeping across everyone as he threw out the most cruel reality:
“With the current medical supply reserves in Linbei City, if we fight recklessly…”
“Our supplies are enough for only one battle. After one battle, the wounded soldiers will have no medicine to treat them. They can only wait to die.”
These words struck Pei Yi’s heart like a heavy hammer.
It turned out that medical care was also a deadly shackle around their necks.
The military council had not yet completely ended when irritating commotion came from outside.
Qu Detao, the imperial supervisor sent by the imperial court, had barely arrived at Linbei City before impatiently making trouble.
As soon as he arrived, he made a great show of demanding inspections of the military grain, troop registers, wounded camp, and military pay.
Xiao Yuan’s eyes darkened slightly, yet there was no trace of panic.
He quickly made his decision. “Pei Yi, you go back. Chief Secretary Xia, come with me. Banyue, continue investigating the intelligence.”
He straightened his sleeves, his tone cold. “As for Qu Detao… let him investigate. Whatever he wants to see, let him see it.”
“But if he wants to touch something he shouldn’t, leave his hand behind first.”
◇◆◇◆◇
As everyone left, the study immediately became empty.
Su Mu Chen was pondering whether he should first return to Guichen Studio and have Su Qianqian quickly prepare all the medical supplies that could be mobilized, when Xiao, who had been sitting quietly the entire time, suddenly called out to him.
“Mu’an, come with me.”
“Oh, okay…”
Su Mu Chen followed his footsteps out of the study and discovered that they were heading in the direction of the southern courtyard.
The two walked in silence all the way until Xiao led him into his residence in the southern courtyard.
Xiao walked directly to the cabinet, opened the door, and took out a large black tactical backpack from the very back.
Su Mu Chen recognized it at a glance.
It was the “combat backpack” that Xiao had specifically made a list for earlier and asked him to have Su Ningning prepare in the modern world.
Xiao unzipped the backpack and methodically took out several items, placing them one by one on the table before pushing them toward Su Mu Chen.
A specially made folding knife, a small smoke grenade, two cans of high-pressure riot-control spray, a black rectangular compact first-aid kit, and a matte-black tactical protective vest.
He picked up the folding knife first.
It was almost identical to the one Xiao usually used, clearly specially made.
“I know you can’t cut people with this knife.” Xiao handed the folding knife to him. “But you still have to carry it with you. Use it to cut ropes, cut through obstacles, or cut anything other than people.”
Xiao understood Su Mu Chen far too well.
As a doctor who had engraved saving lives into his very bones, Su Mu Chen could precisely cut through flesh with a surgical knife to save someone, but asking him to take a knife and stab or kill someone was a psychological barrier he simply could not overcome.
He had previously given him a high-voltage stun baton, but this young master had never once thought of using it. By now, no one knew which corner it had been stuffed into to gather dust.
Next, Xiao pointed at the smoke grenade. “This is a smoke grenade. If you encounter a blockade, throw it onto the ground. It will buy you time to escape.”
Then he pointed at the two cans of riot-control spray and raised his brows. “You don’t use the stun baton, and you can’t bring yourself to cut people with a knife. You can at least press this riot-control spray, right? Spray it directly into their eyes.”
Su Mu Chen silently nodded and committed each of these things to memory.
“This is a portable tactical medical kit. It contains rapid-hemostasis bandages and powerful painkillers.”
Xiao pointed at the small black pouch.
Finally, Xiao picked up the matte-black vest, his expression becoming serious.
“This is a protective vest specially made for the Gatekeeper team. Wear it beneath your clothes. Although its material cannot completely block a heavy sword or the strike of a sharp axe, its fibers can reduce the impact of sharp blades and provide a certain degree of protection.”
Xiao raised his head and looked at Su Mu Chen. Within those deep eyes like a cold pool, a trace of extremely difficult-to-detect meaning flashed past.
“I am giving all these things to you now. You decide for yourself how you should use them.”
“…”
Su Mu Chen lowered his head and looked at those things, falling into a brief silence.
He could easily return to Guichen Studio and have Su Ningning prepare another set. There was absolutely no need to use Xiao’s supplies.
Moreover, there was currently only this one specially made protective vest. As an adviser, if Xiao later needed to carry out some high-risk mission for Xiao Yuan, he clearly needed this layer of protection more than Su Mu Chen did.
Yet Xiao had handed him these life-saving things without hesitation.
Su Mu Chen’s mind involuntarily recalled what Xiao Yuan had once said to him:
“Xiao has not experienced these things for the first time.”
Could it be… that in some “past” Xiao had experienced, he had died because he lacked these things?
Su Mu Chen suppressed the thoughts churning within his heart. He did not refuse and solemnly put away those few items.
“Mm, I understand. Thank you.”
Since Xiao had told him to “decide for himself” how to use them, then, in his heart, he already knew the true destination of this vest.
He raised his head and looked seriously at Xiao. “But you also need to be careful.”
Hearing this, the corners of Xiao’s lips curved into a half-smile. “Don’t worry. I don’t have many enemies here.”
He paused, his gaze landing on Su Mu Chen.
“There are far more people who want the life of ‘Doctor Su’ than those who want mine.”
“That’s not funny.” Su Mu Chen slightly furrowed his brows.
He knew very clearly in his heart that an innocent man could get into trouble because of his wealth.
Once those forces hostile to Xiao Yuan discovered his existence and the medical and material value he could bring, he would become the primary target that everyone wanted to eliminate.
Xiao Yuan’s enemies were his enemies.
“We’re about to enter the true period of wartime. There are too many variables on the battlefield. No one can guarantee what will happen.”
Xiao’s tone was very calm, yet carried a heaviness like a storm approaching.
“Once war begins, even His Highness or I won’t be able to stay by your side every day. Although His Highness will definitely send hidden guards to keep a close eye on you, it is always better for you to prepare some means of self-defense yourself.”
“I know that with your temperament, you absolutely won’t obediently stay in the modern world and wait for news.”
Xiao stared intently into his eyes, his tone carrying a trace of warning. “But remember this yourself. If you are gone, His Highness won’t be able to live well either.”
Su Mu Chen’s heart suddenly tightened.
In the past, he had always heard other people talk about what would happen after he was gone.
But he seemed to have never truly thought deeply about it…
If he died in this chaos, what would happen to Xiao Yuan?
Xiao Yuan… would probably collapse, or fall into extreme pain.
But very quickly, Su Mu Chen’s rational mind immediately thought of an even more cruel and realistic question.
If he died, as the “Key to the Door,” he would disappear, the Door would close—what consequences would that trigger?
He suddenly realized that his life had long since stopped belonging only to himself.
If he died, the Northern Frontier would never again be able to obtain any modern strategic supplies.
Would those workshops that had only just begun, that supply system that had only just been established, all be cut off overnight?
It turned out that, without him realizing it, his life had already become connected to so many people.
Perhaps one day the Northern Frontier would no longer need Guichen Studio.
But that day was not now.
Then his thoughts shifted, and he thought of the person before him.
If he were gone, what would happen to Xiao?
Xiao would probably be sad for him too.
But what he thought of was the even more chilling “rule” hidden beneath Xiao’s calm exterior.
“Then you…”
Su Mu Chen carefully considered his words, his mind spinning wildly.
He knew that he absolutely could not directly ask, “What are the conditions for rebirth?” or “How is the time loop triggered?” because that would definitely violate the Door’s taboo. Xiao would certainly be unable to answer, and might even suffer backlash.
He could only carefully piece together the clues from the past.
Xiao had repeatedly saved Xia Lan Shi before, even at the cost of paying an enormous price.
It could not be ruled out that this was because Xiao had a special emotional bond with Xia Lan Shi.
And Xiao’s protection of him was just as strict, even to the point of handing over his own trump card for survival.
Of course, this could be concern between friends and family, but… it also could not be ruled out that it was because he was the “Key to the Door.”
If the Key to the Door died, then what would happen to the Gatekeeper?
“…What would happen then?” Su Mu Chen ultimately asked only these four cryptic words.
“…”
Xiao looked at him in silence.
He was too smart.
Xiao thought.
Sooner or later, Su Mu Chen would piece together that bloody secret that absolutely could not be spoken aloud from these fragments of clues.
Xiao thought for a moment and decided to answer him in another way.
He calmly said, “Do you remember what we said the first time we met at Guichen Studio?”
Su Mu Chen froze for a moment, recalling that memory that was not actually that long ago.
At that time, he was overwhelmed by the enormous debt that had fallen from the sky.
He only remembered that Xiao had been dressed in black, called him “Young Master Su,” and said that he was a “shop assistant” at Guichen Studio.
As for the other details, his mind had been too chaotic at the time, and he really could not remember them clearly.
“I remember. At that time, you anxiously asked me where Guichen Studio’s account books were,” Xiao reminded him softly.
With Xiao’s reminder, Su Mu Chen suddenly recalled that scene and could not help giving a bitter laugh.
“Right. I was almost going crazy then. I asked you whether you had ‘cloud data.’ And then you actually—”
Su Mu Chen’s voice abruptly stopped.
He remembered.
At the time… Xiao had looked at him, slowly raised a finger, smiled, and pointed at his own head.
Back then, Su Mu Chen had thought that this shop assistant was mocking him and had been so angry that he wanted to hit him.
But now, when Xiao brought up this old matter again at this point in time…
Su Mu Chen paused for several seconds, his mind seeming to have been struck by a thunderbolt.
Cloud data…
His head…
Could it be…
Could Xiao be hinting to him…
That all those “pasts,” all those memories of things that had once happened, were all like cloud data, perfectly intact, backed up inside Xiao’s mind?!
Su Mu Chen’s pupils suddenly contracted as he stared at Xiao in shock.
He could not imagine how despairing it would be for someone to carry the memories of everyone’s deaths and return to the starting point again and again.
“From the moment I became the Gatekeeper,” Xiao looked at Su Mu Chen’s shocked expression. Knowing that he had understood, he calmly continued, “the Door is not merely—”
“Stop! Stop, stop, stop!”
Su Mu Chen abruptly came back to himself, his face deathly pale. He grabbed Xiao’s arm and urgently interrupted him. “Don’t say anything else! Don’t say another word!”
Su Mu Chen’s heart was beating wildly.
He was afraid.
He was afraid that if Xiao continued, he might accidentally touch that invisible boundary. What if it triggered the “Door’s punishment” again and caused Xiao to endure that kind of pain capable of tearing even the soul apart?
Since he already knew the answer, there was absolutely no need for Xiao to risk his life to confirm it for him.
Seeing Su Mu Chen looking so anxious he was practically jumping, yet with nothing but concern in his eyes, Xiao was slightly stunned.
Then he gently smiled.
It was a smile in which he had completely lowered his guard, a smile that came from the depths of his heart.
“Don’t worry. Your older cousin isn’t that stupid.” Xiao gently patted the back of Su Mu Chen’s hand, which was tightly gripping his arm, his tone becoming somewhat lighter. “Besides, I’m afraid of pain too.”
He put away his smile.
“I only brought this up because I wanted to tell you—” Xiao’s voice was very soft, yet it struck Su Mu Chen’s heart heavily:
“…I’ve seen enough.”
He released his hand and took half a step back, giving his final plea:
“So… this time, no one is allowed to be missing.”
◆◇◆◇◆
After Su Mu Chen left the room, Xiao turned around and opened the enormous tactical backpack once again, taking out a heavy black hard-shell case from inside.
His fingertips gently brushed over the matte, non-slip carbon-fiber texture on the surface of the case, finally stopping on a silver-black metal nameplate in the center of the lid.
Cold light flowed across the nameplate, where a line of words had been cleanly engraved—
“COMMON RAVEN SEVEN.”
“It’s time for ‘you’ to make your appearance.”
Xiao lowered his eyes and murmured.