Here, it is a translation of the given Chinese content into English.

This was the first time in the three years since Fan Xian entered the capital that he had planned something entirely on his own. Without the help of the old men, without Yan Bingyun's schemes, he could still use the Overwatch Council's vast intelligence system and the immense archival resources accumulated over the years to begin extending the tentacles of his conspiracy from outside the palace walls, reaching within.

The pressure was immense, but he had to learn to bear it. In the process of preparing for this, it wasn't that he hadn't considered telling his father and Chen Pingping the truth. However, these two elders were so inscrutable; no one knew the extent of their loyalty to His Majesty, nor was it clear whether such a conspiracy, one that would certainly throw the royal family into chaos, would be forcibly suppressed by the two elders for some reason.

So, he chose to walk alone in the darkness.

Intelligence from the Overwatch Council was continuously delivered to his study. To avoid attracting the attention of those with ulterior motives, Fan Xian used a clever guise, cautiously touching only peripheral information, which was then passed through several hands to that secluded, quiet courtyard in the city.

He didn't dare remain silent in his study for too long, lest he reveal any clues. He continued to be filial to his father as usual, enjoying leisure in the garden. He even paid a visit to Ren Shaoan's residence, though Xin Qiwu did not invite him as in previous years.

Fan Xian understood that Xin Qiwu was, after all, a close associate of the Crown Prince. At this crucial moment, as the Crown Prince gradually awoke from his silence, using his excellent performance to deceive everyone in the palace, Xin Qiwu had undoubtedly received instructions from the East Palace to no longer attempt to win him over. However, this shift was not abrupt. Xin Qiwu found a suitable excuse and even personally delivered a generous gift to his residence.

Several days later, Fan Xian finally had a relatively clear understanding of the matter's ins and outs. After running through the plan in his mind, standing from the perspective of a post-event investigator, he scrutinized the clues in his mind with cautious eyes. He confirmed that a top-down investigation by the royal family would be hard-pressed to implicate Hong Zhu, let alone himself. Only then did he feel a little relieved.

On the seventh day of the New Year, Fan Siz辙, bored out of his mind from being confined to the residence, pestered his elder brother to go out for a stroll. Fan Xian glared at him and rejected him, "Do you think you're still the Second Young Master of the Fan Residence? The council is concealing your whereabouts... but the palace certainly knows where you are... The Ministry of Justice hasn't come to arrest you because the palace is giving face to Father and me, your elder brother. If you go out flaunting your chubby face like that, where will the palace's face be? Someone will come to arrest you immediately!"

Fan Siz轍 was taken aback, wondering why his brother was speaking so harshly today. However, from his year of doing business in Northern Qi, he had retained his scheming genius from those years, and shed some of his superficiality. He immediately saw that his elder brother was troubled and in a heavy mood. He said ingratiatingly, "Brother, what's wrong? We're brothers for life. If there's anything you want to say, tell me. See if I can help you."

Fan Xian suddenly thought of the few Northern Qi experts who had come south with Si辙, now arranged on a manor outside the city. He was slightly moved, but immediately dismissed the thought. He didn't dare to disturb even Director Chen and his father, let alone his precious younger brother. It was just that Si辙 had seen through his worries, so he needed a cover.

He paused slightly and said, "On the tenth day of the month, the First Prince's mansion will open its doors to guests. I'm going too."

"The tenth day of the month?" Fan Siz辙 pursed his lips and said with a grin, "Brother, that's a big day. It seems the First Prince really values you... to choose such a day to invite you."

Fan Xian sneered, "I'm afraid it's the Princess Consort's intention... What am I worried about? I said I wanted to bring Hongcheng, but yesterday someone from the Prince's mansion came to remind me that on the tenth day of the month, our Second Prince will also be there."

Fan Siz辙 gasped, "Good heavens... Brother, you beat the Second Prince into a pulp. Now you have to sit at the same table and eat? Be careful that woman plays dirty."

Fan Xian frowned and said, "It won't come to that... Who would dare to kill someone at the First Prince's mansion? It's just... I feel it will be difficult to deal with."

Fan Siz辙 lowered his head and immediately understood what his brother was worried about. The First Prince had chosen the tenth day of the month to host guests, inviting both Fan Xian and the Second Prince. It seemed that the First Prince still harbored the idea of letting his two "brothers" be at peace again. His brother couldn't possibly refuse to give face to the First Prince, but... he certainly couldn't let the Second Prince off easily. No wonder he was so troubled.

He thought he understood the reason for his elder brother's heavy heart and shook his head, "Just go and eat. Don't respond to anything they say. The First Prince can't do anything to you."

Fan Xian smiled, "That makes sense too." He looked at his younger brother and suddenly said, "You really want to go out? You can't get out of the carriage, you can only look from inside."

Fan Siz辙 was overjoyed, looking at him pitifully. Since returning to Qing from Northern Qi, he had been confined to the residence. Even on the first day of the New Year, he could only kowtow a few times in the carriage during the ancestral sacrifice. He was already stifled to death. Hearing his elder brother's order, he nodded repeatedly.

...

...

Snowflakes, like willow catkins, gently fluttered down as the carriage toured Kyoto.

The Fan brothers took two rounds on Kyoto's bustling streets, stopping by Danbo Bookstore in the middle to get an understanding of the recent situation. With the two owners here, the shopkeeper of Qing Yu Tang who had replaced Qi Ye quickly boarded the carriage to report. However, listening to the report was secondary. Fan Siz辙 just wanted to see this small bookstore where he had started his business.

Leaving Danbo Bookstore, they went to Baoyue Brothel.

The carriage stopped outside the discreet back door on the side of Baoyue Brothel. Fan Siz辙 tilted his face and looked up at the three-story building, his young face filled with the sighs of an old man. Looking at Danbo Bookstore earlier had already made him quite sentimental. Now, looking at this brothel that had changed his life's destiny, those complex feelings surged into his mind all at once.

Fan Xian lifted the carriage curtain and got out, saying, "Let's go."

Fan Siz辙 was overjoyed, saying nothing and following him out of the carriage.

Someone was already waiting at the back door. The group quietly entered the backyard and went straight up to the third floor along the quiet staircase, sitting in the room that had always been kept empty.

Fan Siz辙 excitedly twisted his head, looking around, his hands occasionally touching the Wei-style antique furniture he had personally arranged, his face full of reluctance and excitement.

Fan Xian smiled and glanced at him, not worrying about his younger brother's safety. In Kyoto, as long as he came out with him, no one would dare to forcibly do anything. It was just that looking at Fan Siz辙's expression, his emotions suddenly stirred... Guys like Si辙 and the third child, if judged by good and evil, would probably be skinned alive, yet he had always stood firmly behind them.

He thought with a self-deprecating smile that he really wasn't a good person.

There was no one else in the room, only Sang Wen and Shi Qing'er personally serving them. After drinking a cup of hot tea, Fan Xian gave Sang Wen a look, and the two walked to the hidden secret room in the back.

Fan Siz辙 wasn't surprised, not even glancing at them. He just continued chatting with Shi Qing'er, his words showing great concern for the management of Baoyue Brothel after he left Qing. When he heard Shi Qing'er recount Fan Xian's slight innovations to Baoyue Brothel, as well as the contract situation of the girls in the brothel, he opened his mouth wide and gasped, the look in his eyes toward the secret room changing.

Fan Siz辙 truly admired his elder brother from the bottom of his heart. With this change, it seemed the brothel was taking a loss, but in reality, it was winning people's hearts and reducing too many unnecessary dark expenses.

He shook his chubby face and secretly sighed, "I only know how to earn silver, but my brother knows how to win hearts."

...

...

What Fan Xian wanted was the loyalty of his subordinates. Baoyue Brothel's important use, besides extracting silver from the powerful and wealthy, was intelligence gathering, and this work could only be handled by the loyal Sang Wen.

"Have you been to Chen Garden recently?" Fan Xian asked the gentle woman, seemingly casually.

Sang Wen shook her head, "No."

Fan Xian nodded. Sang Wen was his direct subordinate. As long as Chen the Cripple didn't speak, the council's regulations and corresponding work processes couldn't interfere with her actions.

"How's the thing I asked for prepared?"

Sang Wen took out a sealed kraft paper bag, handed it over, and said, "The intelligence about the Embroidery Bureau was easy to obtain, but... the matter you want to investigate is difficult to start."

She said with a wry smile, "The medical officers of the Imperial Hospital are all old men. Where would they come to visit a brothel? If you really want to investigate the Imperial Hospital, I think it's more convenient to start from the council."

Fan Xian shook his head and said, "I said beforehand that this matter is private and must not go through the council... Also, the imperial physicians are all old men, but what about their apprentices? They're all young people."

Sang Wen's lips were a bit wide, but not at all ugly. On the contrary, they had a special charm when paired with her gentle face. She opened her mouth and said bitterly, "Those students of the Imperial Hospital have too little pay. They can't diagnose alone until they graduate. Even the various residences in Kyoto aren't allowed to go... It's really difficult for them to come to Baoyue Brothel."

Fan Xian took out the dossier from the kraft paper bag, squinting his eyes and looking closely. Relying on his memory that was far superior to ordinary people, he forcibly memorized most of the key content on the dossier and handed it back.

Sang Wen took out a brass basin, put the dossier and kraft paper bag in the basin, carefully burned them, and only stood up after they were all reduced to ashes.

Fan Xian digested the information in his mind, closed his eyes, and shook his head, saying, "That's all from your side."

Sang Wen bowed slightly and said, "Yes."

Fan Xian left Baoyue Brothel with his younger brother, but he didn't stay in the residence. After sending Si辙 back, he got into the black carriage again.

He thought in the carriage that whether it was the peripheral intelligence obtained from the Overwatch Council or the bits and pieces of information grasped by Baoyue Brothel, they only led to a relatively vague conclusion.

The Crown Prince's change did indeed start half a year ago. At that time, Fan Xian was far away in Jiangnan, and had no idea what was happening beneath the calm surface of Kyoto. But... without a doubt, the venereal disease that had been troubling the Crown Prince and making his mental state seem somewhat inferior and weak had been cured. This matter caused the Imperial Hospital, who knew the inside story, to collectively rejoice, believing it to be a blessing from heaven, bestowing fortune upon Qing.

It was also from that time that the Crown Prince, due to his physical recovery, began to exude a brilliance called confidence, and became more calm, revealing the composure that a future emperor should have.

The Empress Dowager liked this change very much, and His Majesty seemed to have some unexpected joy as well.

After getting confirmation from Hong Zhu, Fan Xian fell into some kind of contemplation. From a psychological level, he could deduce certain things, but... the Eldest Princess might just be treating the Crown Prince as some kind of substitute, even as a pet rabbit. But what about the Crown Prince? Even if he was the passive party, where did he get the courage?

Whether it was the former Crown Prince's timidity and self-esteem, or the current Crown Prince's composure and self-control, he shouldn't have had the courage to do such an absurd thing. Although it was politically beneficial, the Crown Prince still didn't seem like someone with that kind of courage, because he wasn't crazy enough.

So, before agreeing with Hong Zhu, Fan Xian first did was to investigate the cause of this matter, feeling that it was really a bit strange.

The carriage bumped along, and Fan Xian's brow was furrowed tightly. As a disciple of Fei Jie, he was too familiar with drugs, so after roughly understanding the whole situation, he subconsciously turned his suspicious gaze to... medicine.

Medicine.

In this world, although venereal disease wasn't an incurable disease, it was also a troublesome thing that would make people bedridden and very difficult to bear. Otherwise, the Crown Prince wouldn't have suffered for so many years, and the Imperial Hospital wouldn't have been troubled for so many years in secret.

What kind of medicine could cure the Crown Prince in such a short time? And what kind of medicine could make the Crown Prince so much bolder?

So he arranged for Sang Wen to start investigating this line of clues, using other reasons, of course. However, after investigating, he found that the back of this clue was a fog. Baoyue Brothel's intelligence power was limited, and the auxiliary investigation on the Overwatch Council's side had not made any progress.

Fan Xian began to feel a trace of danger, as if a cold gaze was watching him from behind. Was this a trap? Could someone have set up a game, but let himself reveal these things?

If he continued to dig deeper, he was worried that he would alarm the powerful figure hidden behind the scenes, so he decisively interrupted the investigation of the medicine and returned to the path he should be on.

Because he had understood one thing: no one knew about his relationship with Hong Zhu. In that case, no one should think of using this relationship. If there really was another hand trying to control this event, then it had the same purpose as his. As long as it didn't involve him when the incident occurred, that hand couldn't use him.

Medicine was key, but it wasn't key. The key was the Crown Prince's heart. Medicine might play a role in fueling the flames, but this way of doing things was really rare and powerful. Fan Xian guessed that if the medicine really had a problem, who would have done it?

In an instant, several names immediately appeared in his mind. Those who had the motive to do such a thing were no more than himself, who always wanted to bring down the Eldest Princess and the Crown Prince, and the Second Prince, who had the help of the Ye family but was beginning to faintly feel that the Crown Prince was going to snatch his position in the Eldest Princess's heart.

It might even be... the Emperor.

Fan Xian in the carriage was startled, subconsciously shaking his head. Although he had always been wary of the Emperor, the Emperor had really treated him well, and didn't seem like such a person. Moreover, not to mention that the Emperor himself was very sorry to the Eldest Princess, even if he wanted to clean up the court, where would he condescend to use such a dusty method?

Of course, the first name that came to Fan Xian's mind was actually Chen Pingping, because from the medicine, he naturally thought of Fei Jie. But he couldn't find anything, and he didn't dare to risk investigating, so he naturally couldn't confirm anything and had to give up.

The carriage drove to a secluded residence, which was the one that Wang Qinian had bought with a few hundred taels of silver. Fan Xian went straight in, moved a chair in the innermost room and sat down, silently looking at the withered old man opposite him.

Wang Qinian said with a bitter face, "Zi Yue bid farewell outside. He's going to Northern Qi tomorrow. Mu Tie doesn't dare to take over the command..."

Fan Xian waved his hand to stop him and said directly, "You know I don't want to hear these things."

"You can go to Lord Yan," Wang Qinian said with a mournful face. "This humble official is not good at this... Besides... this is a crime punishable by nine generations of relatives."

Fan Xian glared at him and said, "What crime is there? It wasn't us who made this mess."

Wang Qinian looked at him fearfully, thinking that even if it wasn't punishable by nine generations of relatives, but he knew that thing. If the people in the palace knew, even if his wings of the Overwatch Council were able to fly... he would probably not escape death.

Fan Xian smiled gently, patted his thin shoulders, and said, "What does this mean? This means you are the person I trust the most... Besides, you know all about my affairs, and any one of them is a matter of losing my head. Are you afraid of one more?"

Wang Qinian suddenly regretted that after returning from Northern Qi, he should have taken over the command immediately according to Master Fan and the Director's wishes, instead of returning to Master Fan's side to take charge of the Qinian Team again. If he had, he would definitely not have seen the box that he shouldn't have seen even if he was blind, and he would definitely not have heard the secret news that he shouldn't have heard even if he was deaf.

...

...

"Someone is investigating." In Chen Garden, amidst the light snow, Chen Pingping, sitting in a wheelchair and draped in a thick fur coat, looked at the ice scum gradually freezing on the surface of the pond in the garden, smiling and saying, "They are investigating very cleverly, hiding very deeply, and we can't confirm who it is yet."

Fei Jie glanced at the Director and shook his head, "There are still three months before the scheduled time. I hope there won't be any trouble."

"I wonder if the crazy girl has noticed anything." Chen Pingping sighed, "But Miss said that the real death of a camel only needs to add the last straw... I won't live for a few years, this straw must be put on as soon as possible."