The renovation work on the Northern Frontier Administrative Office had never stopped.
Most of the main buildings were already completed. The damaged roofs had been replaced with new tiles, the walls had been replastered, and the window paper had been replaced as well.
The rooms within the administrative office were gradually being assigned. The front courtyard was used for official work and meetings, while the rear courtyard was allocated to the main officials.
There was still a great deal of work left unfinished in the rear courtyard, but so that the residents would not have to wait too long, the main rooms of each courtyard had already been prioritized and completed.
Xiao Yan lived in the main courtyard, Chi Banyue in the north courtyard, while Xia Lanshi lived in the east courtyard.
The south courtyard was used as a guest courtyard and was usually empty.
The west courtyard had not yet been occupied.
The east courtyard was not large, but its layout was square and orderly. The windows faced south, allowing sunlight in during the day. Even though the winter sun of the Northern Frontier was not warm, it was still much better for keeping out the cold than a tent.
Several cinnabar plum trees and a wintersweet tree had been planted in the corner of the courtyard. When Xia Lanshi moved in, tiny flower buds had already formed on the branches. They had not yet bloomed, but it was clear they were gathering strength.
Xia Lanshi personally arranged each of the belongings he had brought with him.
Books, medicine boxes, several changes of clothes, a paper umbrella, a qin, a chessboard, an incense burner, and a potted golden-splashed plum that he had tended for several years.
There were not many belongings. Most of them were documents.
Sitting by the window of the east courtyard, with the lamp burning steadily and the room warm and comfortable, and with the charcoal brazier burning strongly enough, it was much warmer than the days he had spent living in a tent.
He had finished organizing his desk. All the account books and documents on it had already been reviewed and approved, while he had processed half of the new files Xu Wenshan had delivered today.
He planned to rest for a while and take things slowly.
Suddenly, he remembered that when Xiao Yan had returned today, he had passed by his window.
At the time, Xia Lanshi had been writing beneath the lamplight. Xiao Yan had not disturbed him. He had simply left an envelope on the short cabinet beside the door before turning and leaving.
Xia Lanshi had been dealing with the last few documents then and had not had a free hand, so he had not checked it immediately.
Now, he finally had the time.
He got up, walked to the door, took the letter, and returned to the desk.
The envelope was an extremely deep mist-black. There was no name on it, but pressed into it was a tiny, almost imperceptible simplified owl pattern.
Xia Lanshi sat at the desk, with several account books he had already reviewed spread beside him. The ink had dried, and the pages were neatly stacked at the corner of the desk.
The lamplight burned steadily, casting an extremely faint glow across his lenses.
Over the past few days, he had already grown accustomed to wearing glasses. He was accustomed to the words on the page no longer being blurred when his gaze fell upon them, accustomed to no longer having to lean forward until his face was almost against the paper.
But what he was looking at now was not the account books.
He unfolded the letter and read it carefully beneath the lamp.
Once.
Then again.
————————
Young Master Huaiyu,
I have received your letter. I hear that Linbei City is gradually entering the end of winter. That is very good. The wind and snow will always stop eventually. Spring in the Northern Frontier may come slowly, but it has never failed to arrive.
You asked about snow. It rarely snows where I am, but it rains very often.
The rain is very wet, the air is heavier, and water accumulates on the ground. Moss grows on the stone slabs, and it is easy to get your trousers wet when passing by.
But when winter comes, I have also gone up the mountain to watch the snow.
I do not particularly like winter, but I really like the one or two hours just after the snow has fallen.
The light at Guichen House—you were right, Your Highness. It really is always on.
It is not candlelight, but another kind of light, a warm yellow one that cannot be blown out by the wind.
Doctor Su said that we should leave a lamp on for Your Highness, because the shop is dim and he was worried that Your Highness might bump into something.
The glasses were custom-made at Doctor Su’s request. I chose the frame for Young Master Huaiyu. If they are uncomfortable to wear, please be sure to tell Doctor Su. He will find a way to adjust them.
However, after putting on the glasses, please remember to look into the distance after reading documents for half an hour at a time. This is medical advice I heard and am passing along to you.
Also, the plum blossom embroidery is very well done. The owl in particular looks remarkably lifelike, and the sparrow is very lively.
Xiao
————————
The paper was not the xuan paper or hemp paper commonly used in Dasheng. It was smoother to the touch, the edges were cut neatly, and it carried a scent that did not belong to this era.
The letter was not long. Every sentence was as plain as if they were simply chatting about the weather.
When he read, It rarely snows where I am, but it rains very often, his fingertips paused at the edge of the paper.
Rain—
There was rain in the Northern Frontier too, but that kind of rain usually came accompanied by wind and snow, striking the face like tiny needles of ice.
What Xiao was describing was another kind of rain.
Rainwater, moss, stone-paved roads.
Wet, heavy rain that could cause moss to grow across the stone slabs.
He closed his eyes and imagined the scene for a moment, as though he could faintly glimpse the scenery of another world between the lines.
He could not help wondering: if it rained every day, would there not often be flooding?
But it seemed that what Xiao found more troublesome was getting his trousers wet.
Someone was telling him these things in a letter, as though drawing a picture for him of a place he could not see.
He continued reading.
When winter comes, I have also gone up the mountain to watch the snow.
He paused slightly.
There was something in this sentence that he rarely encountered in Xiao’s letters.
There was no probing.
It was not distance.
It was as though someone had gently pushed open a crack in his own world, allowing him to see the light inside.
Then he read:
Doctor Su said that we should leave a lamp on for Your Highness, because the shop is dim and he was worried that Your Highness might bump into something.
When Xia Lanshi reached this line, his gaze paused slightly.
He looked at the words, and the corners of his lips curved into the faintest smile.
Those were words Su Muchen would say.
He had never met Su Muchen in person.
But from Xiao Yan’s descriptions, and from those treatment plans and lists of medicines, he could already imagine what that person was like.
Indeed, he was the sort of person who would worry that Xiao Yan might bump into something in the dark and deliberately leave a lamp burning for him.
And Xiao had written this into the letter, as if casually mentioning it, yet also as if deliberately letting him know.
Xia Lanshi did not know which it was.
But there was a very faint warmth in his heart.
It was not because of Su Muchen’s thoughtfulness. He had never met Su Muchen.
It was because Xiao was willing to write this to him.
He read the line about looking into the distance after every half hour of reading again.
He knew this was medical advice. Su Muchen had probably said something similar to Xiao Yan as well.
But when he read those words in Xiao’s letter, they carried a weight different from ordinary medical advice.
It was as though someone were saying in his own way:
I remember you.
Outside the window, the night remained deep. The wind of the Northern Frontier passed beneath the eaves, making a low, mournful sound.
Yet at this moment, he did not feel cold.
He sat beneath the lamplight, thinking about that rain, the moss growing over those stone slabs, and that lamp that could not be blown out by the wind.
And also…
That person, sitting far away, writing these words.
What had he been thinking at the time?
He had no answer.
But he was no longer in a hurry to find one.
Because he already knew that an answer was not what he wanted.
His fingertips gently traced the edges of the writing.
The ink was a silvery gray, different from the pine-soot ink commonly used in Dasheng. When it settled on the paper, it reflected a cold sheen that did not belong to this era.
He slowly ran his finger along a line of writing, while the scenes described by the words appeared one by one in his mind.
He was somewhat envious of Xiao Yan, because Xiao Yan could open the Door and travel to that world whenever he wished.
He had once heard Xiao Yan say that the world was extraordinarily prosperous.
Once, when Xiao Yan had returned from behind the Door, he had sat beside the desk and, unusually, spoken at length.
He said there were rows of square-column-shaped buildings there, towering into the clouds, higher than any tower in all of Dasheng, as though their tops could touch the edge of the sky.
At night, those buildings would light up.
It was not candlelight or lamp oil, but a kind of light that did not flicker, illuminating the entire city as though it were daytime.
The roads were flat and straight, and there were metal boxes traveling incredibly fast without needing horses.
Xiao Yan had also said that he had seen a kind of box the size of a palm that could make sounds, with people speaking or singing inside it.
Xia Lanshi found it difficult to imagine what such a scene looked like.
He had been sickly since childhood and had been confined to a windowless room.
After entering Prince Su’s residence, he had also spent almost all his time inside the estate.
Only when Xiao Yan had been sent to the Northern Frontier had he accompanied him and begun moving around more.
He still could not completely imagine that world.
But those shapeless images were slowly taking form within his heart.
He folded the letter back up.
Then he put it back into the envelope and stored it inside a hidden compartment.
Although this letter contained no military secrets and seemed like nothing more than casual conversation about everyday life, the very existence of contact with another world was itself a secret.
He had to be cautious.
◆◇◆◇◆
The night was already deep.
Yet the lamp in the east courtyard was still lit. The shadow of a person on the window paper had been bent over the desk for a long time, as though writing.
Xiao Yan stood beneath the corridor, watching that window from a distance without approaching.
He had already been standing there for some time.
The wind passed beneath the eaves and stirred his dark cloak slightly, but he did not move.
He remembered some things.
Those things had originally been separate, like scraps of paper casually scattered across a desk. He had never thought of piecing them together.
But now, they were slowly drawing closer together in his mind, one by one, being pushed by an invisible hand toward the same point.
The pocket watch.
That mist-silver pocket watch had been brought back from Guichen House.
Of the three pocket watches, only one was different.
The person who had chosen that watch was Xiao.
What made it special was not its appearance, but the line someone had personally engraved on it.
The glasses.
That light platinum-colored pair of glasses had also been chosen by Xiao.
When he had handed the glasses to Xia Lanshi, Xia Lanshi had fallen silent for a long time.
At the time, he had thought it was because the glasses themselves were too exquisite.
But there was an embossed owl pattern at the corner of the glasses cloth.
Xia Lanshi had been looking at that pattern.
The letters.
At first, the letters had been initiated by Xia Lanshi. Most of the contents had been related to probing, accompanied by a few words of gratitude.
Xiao Yan had not thought much of it at the time. He had assumed Xia Lanshi simply wanted to confirm whether Xiao was the person who had rescued him on that snowy night years ago, as well as to conduct some probing.
But in the more recent letters, Xia Lanshi had never mentioned their contents to him again.
Xiao Yan did not know what those letters contained.
He only knew that Xia Lanshi’s expression when writing and receiving letters had changed.
Xiao Yan turned and walked toward the north courtyard.
The lamp in the north courtyard was also still lit, warm yellow light shining through the window paper.
Chi Banyue was already preparing to retire for the night.
She had just removed her hairpin and let her long hair fall over her shoulders. She still held a comb in her hand and was about to extinguish the lamp.
When she heard footsteps outside the door, her movements stopped.
Xiao Yan did not knock, but neither did he push the door open directly.
He simply stopped outside, his voice passing through the door.
“Banyue, there’s something I want to ask you.”
Chi Banyue put down the comb, draped her outer garment over herself again, and walked to the door to open it.
She saw Xiao Yan standing beneath the corridor. His expression was no different from usual, but Chi Banyue had known him for long enough to distinguish the extremely faint layer of scrutiny being suppressed in his eyes.
She stepped aside to let him pass.
“Your Highness, come in.”
When Xiao Yan entered the north courtyard, his gaze swept across the empty teacup on the desk, the short blade placed beside the pillow, and the dark-green outer robe casually left on the clothes rack.
He sat down at the desk without exchanging pleasantries and got straight to the point.
“Huaiyu and Xiao have been corresponding frequently recently.”
He looked at Chi Banyue.
Xia Lanshi and Chi Banyue were privately as close as siblings. Chi Banyue cared deeply about Xia Lanshi, so she knew some things that he did not.
Chi Banyue’s fingers stopped at the edge of her collar.
She did not move.
Her expression did not change, but she remained silent slightly longer than usual.
Long enough for Xiao Yan to notice.
“Yes,” she said. “What does Your Highness wish to know?”
“What do they write about?”
Chi Banyue thought for a moment before answering.
“At first, it was probing. He only wanted to know whether Xiao was the person who rescued him back then.”
Xiao Yan did not interrupt.
“Later, once he confirmed that he wasn’t, he stopped probing.” Chi Banyue’s tone was as calm as if she were reporting official business. “The later letters were mostly just everyday greetings. They talked about the weather in the Northern Frontier, the current situation in Linbei City, and occasionally asked what the world on the other side was like.”
“You’ve seen those letters?”
“No,” Chi Banyue said. “But sometimes he mentions things. He said that Young Master Xiao’s replies never contain probing questions or flattering words. They simply…”
She paused, as though searching for the right word.
“They simply describe ordinary things.”
She did not say that Xia Lanshi had also mentioned that Xiao would write words of concern.
But those could also be included among “ordinary things.”
Xiao Yan remained silent for a while.
His gaze fell on the lamp at the edge of the desk.
Then he said directly, “He chose the pocket watch. He engraved the words himself. And he chose the glasses too.”
Chi Banyue said nothing.
She knew what Xiao Yan was suspecting.
“The words engraved on the pocket watch,” Xiao Yan continued, “that line. I feel that it isn’t simple.”
On the surface, the words As long as you live, that is enough seemed like a form of encouragement.
But as words of encouragement, they were somewhat too heavy, too helpless.
That was Xiao—the person capable of wrapping major clues inside something as casual as “go for a walk.”
He had always thought that perhaps those words were another major clue.
And perhaps it was one that only Xia Lanshi could understand.
Chi Banyue lowered her head, as though considering how to respond.
She knew very well what Xiao Yan was thinking.
She had known Xiao Yan for long enough to tell that his expression at this moment was not anger.
He was reassessing certain things.
“Your Highness,” she said, her tone calm, yet carrying a certainty even she was not completely confident in. “Xia Lanshi only wants to win this person over. Young Master Xiao is Doctor Su’s distant relative, a core figure protecting Doctor Su, and also the Gatekeeper of the Door. If he can establish a good relationship with him, it will benefit the Northern Frontier, Your Highness, and the plan.”
Xiao Yan remained silent upon hearing this.
He naturally understood all of this. Xia Lanshi himself had once said, “Bring him a little closer.”
That was very much in keeping with Xia Lanshi’s style.
Anyone useful had to be retained, regardless of the form that relationship took.
Chi Banyue continued, “He has always known his limits when doing things. Your Highness knows that better than anyone. He simply… isn’t accustomed to saying everything out loud.”
Those words fell into the room, and Xiao Yan’s gaze shifted slightly.
Chi Banyue was right.
Xia Lanshi indeed never said everything.
He would use pens, paper, and carefully chosen words to disguise his intentions.
Xia Lanshi also maintained correspondence with certain specific people, using it to gather hidden intelligence.
After a long while, Xiao Yan finally said, “I understand.”
He did not ask any further questions.
When he reached the door, he paused.
“Get some rest early.”
Chi Banyue answered, “Yes.”
The door closed behind Xiao Yan.
Chi Banyue sat at the desk, listening as his footsteps gradually faded beneath the corridor.
She did not relax.
Because from Xiao Yan’s final words—I understand—she sensed not relief, but a quietness that was gathering strength.
She picked up the comb but did not continue combing her hair, instead thinking back over what had just happened.
Xia Lanshi had been protected by Xiao Yan since he was ten years old. The two of them had spent years together like that, but it had only ever been a relationship between lord and subject.
But now, something was different.
Xiao Yan had never previously concerned himself with Xia Lanshi’s private affairs.
He genuinely cared about Xia Lanshi.
That kind of concern could sometimes be harder to deal with than neglect.
She could also tell that Xiao Yan was extremely wary of Xiao, because Xiao was hiding too many things, making it impossible for Xiao Yan to trust him completely.
She could only silently hope that this connection could remain hidden for a little longer.
For so many years, the only person Xia Lanshi had ever fallen for was the person who had once saved him on that snowy night.
Now that he had finally managed to let go, another person he cared about had appeared.
No matter what, she had to help him maintain this relationship properly.
◆◇◆◇◆
The next morning, when Su Muchen woke up, warm white light was already filtering through the window.
He lay in bed for a while before realizing where he was.
The room smelled of old wood and dust. Outside the window were the familiar quiet sounds of Changning Alley, occasional miscellaneous noises, and the faint clinking of the copper lock when a neighbor opened a door.
There was no sound of waves.
No hum of an air conditioner.
No stuffy, humid scent of tropical plants.
When he sat up, he felt as though he had slept for a very long time, so long that his body no longer remembered the last time he had slept this deeply.
When he got out of bed, his footsteps felt slightly unsteady, like someone who had just returned from a long journey, his body still carrying a little of the sluggishness of jet lag.
When he walked down the stairs, his footsteps stopped.
The first floor of Guichen House had already been completely restored to its original appearance.
The counter was back in its original position. The several temporary tables that had been pushed together were gone.
The maps and red pen markings on the wall had all been removed, leaving behind only extremely faint traces of tape.
The coffee machine in the corner was gone, replaced by several plants that had been moved back to their original positions.
The window had been pushed open a crack. The morning breeze was slowly flowing inside, carrying the scent of the stone-paved street and damp air.
Everything seemed to have returned to normal.
Su Muchen stood at the turn of the staircase and watched for a moment.
He remembered the small command center he had seen when he returned last night.
Now all traces of it had disappeared, as though a dream had been carefully cleaned away.
He did not know when it had been tidied up.
Perhaps after he went upstairs last night.
Perhaps before dawn.
As he walked down the last few steps, he saw a box sitting on the counter.
It was deep gray-blue, with no markings on its surface.
Xiao’s voice came from the doorway leading to the back courtyard.
“Awake?”
Su Muchen turned his head and saw Xiao standing by the doorway to the back courtyard, holding a cup of hot coffee.
There was a very faint fatigue on his face, almost impossible to detect, as though he had not slept all night—or had slept only for a very short time.
“What time did you clean everything up?” Su Muchen asked.
Xiao did not answer directly.
Instead, he walked to the counter and pushed the deep gray-blue box toward him.
“Your new phone.”
Su Muchen looked down at the box.
He opened the lid.
Inside lay a phone in a misty blue color, with rounded edges and no logo or brand name on its surface.
The body had a matte-metal finish and felt warm and smooth to the touch.
He picked up the phone and turned it over.
There was only a flat, unmarked, mist-blue surface.
He pressed the power button on the side.
When the screen lit up, there was no brand startup screen.
There was only an extremely minimalist blue-gray circular icon, like a moon phase simplified to the absolute limit.
“No brand?” he asked.
“No,” Xiao said. “It was made internally by the group. You can’t buy it on the market.”
Xiao took the phone and gave him a brief demonstration and explanation.
The phone had no SIM card slot and no IMEI number. It did not rely on any telecommunications network. Instead, it operated through the group’s dedicated satellite channel.
It could not be located by cell towers and could not be locked onto.
The communication channel was encrypted. When a message was sent, it was broken into fragments, transmitted through different satellites, and then reassembled. Even if intercepted, it could not be reconstructed.
“There’s also tracking,” Xiao said, his tone as casual as if he were explaining an everyday matter. “GPS and the group’s own satellites. Dual-layer. If one layer is blocked, it switches automatically. I can see where you are at any time.”
Su Muchen lowered his head and glanced at the phone.
“Last time I had six tracking patches on me. What about this time?”
Xiao was silent for a moment, then smiled slightly.
“This time, they’re somewhere else. They won’t be detected.”
Su Muchen did not ask further.
He knew Xiao would not tell him everything.
But he was also beginning to get used to this feeling of “knowing only part of it.”
Perhaps this was the awareness that came with accepting his fate as the Key to the Door.
Xiao added a few more details.
If the phone was separated from its user for more than five minutes, it would automatically lock.
Unauthorized disassembly would trigger self-destruction. The chip would physically fuse itself, making the data impossible to read.
The screen was matte and privacy-protected. The contents could not be seen from the side.
It was military-grade waterproof and shockproof. It could withstand one meter underwater for thirty minutes, and it would not break even if dropped from a height of 1.5 meters.
“And there’s more,” Xiao said. “This phone has a built-in offline AI. It can operate without relying on any network. It’s a model compressed by the group itself. It isn’t very large, but it’s enough.”
He paused.
“It can calculate supply distribution and organize scattered clues. The preloaded knowledge base covers medicine and engineering. Although it can’t completely replace professional judgment, it’s fairly reliable as an auxiliary tool. It just consumes a lot of power.”
There was simply too much information.
Su Muchen was speechless.
After a moment of silence, he said, “Sounds expensive.”
Xiao took a sip of coffee.
“It’s fine. The old man has plenty of money. Spend whatever you want.”
Su Muchen knew that “the old man” meant Su Huaishan.
Xiao and Su Huaishan did not seem to have a very good relationship. At the last family meeting, Xiao had openly talked back to him.
Although he had done the same thing himself.
Su Muchen put the phone into his pocket. It felt slightly heavier than an ordinary phone.
He remembered the day he had been kidnapped, when his phone had been thrown into the sea. At the time, he had even felt a pang over how much the old phone had cost.
This time, the phone would not be so easily hacked.
He hoped he could use it for a long time.
Then Xiao stuffed a smartwatch, earphones, and several other accessories into his hands.
These were all exclusive products made internally by the group as well.
Su Muchen had not been able to afford such things in the past. Now he had some money, but he was still accustomed to spending money only where it mattered.
Having suddenly acquired so much personal technology, he really was not used to it.
Even if all of it was free.
“These are all for your safety,” Xiao said. “More precautions can’t hurt.”
Su Muchen thought about it and felt that made sense.
Who knew what Sheng Chengxiu would come up with next?
More precautions were definitely better.
Xiao stood by the counter and finished the last sip of his coffee.
“Breakfast is in the kitchen. Make it yourself.”
Su Muchen glanced toward the kitchen.
Then he walked inside.
There was a pot of porridge on the stove that was still warm, with a clean bowl and spoon beside it.
He served himself a bowl, sat down, and slowly ate while the light outside gradually moved along the windowsill.
He had come to treasure this peaceful, reassuring kind of daily life more than ever recently.
However, good times never lasted long.
This peace was soon disrupted once again by Sheng Chengxiu’s visit.