Ever since she had perused the *Secret Volutes of Guifang*, Qin Jiuya had harbored a faint premonition: Zuo Ci, the Ghost Physician, might have been privy to the secret formula. However, she had never imagined that all of the Black Moon Four Gentlemen were connected to this matter.
As a healer, Zuo Ci was the most suitable candidate to safeguard the secret of the formula, and his research notes from before his death were indeed a focal point. Yet, she soon noticed something amiss: if Zuo Ci believed his own strength was sufficient, why would he summon the other descendants of the Black Moon to meet years later?
There was likely only one answer: the original Black Moon Four Gentlemen had shared this secret together.
In ancient times, military tallies were often split in two, held separately by the sovereign and the general. She had reason to believe that the oath regarding the secret formula was handled similarly. This was not only to ensure the secret's safety and prevent it from falling into enemy hands all at once but also served a hidden purpose: if one party betrayed the oath and developed different ideas for the formula, the secret would not fall entirely into one person's hands, and the other three could find ways to restrain them.
As it turned out, this consideration had been prudent.
However, if Di Mo was indeed Wen Dimu, what could have happened back then to make a man destroy his oath overnight, betray his closest friends, and descend into darkness to become the master of the world's most notorious manor?
Qin Jiuya felt that the answers to all of this might be hidden within the origin of the secret formula.
Now that she had laid the core of the matter on the table, the four men remained silent.
The conversation had reached another stalemate. Qin Jiuya didn't bother looking at their expressions. She had no intention of inflating her own status in this discussion; instead, she shifted the focus and brought up their "ancestors."
"Setting aside whether Di Mo is hiding in some corner waiting to laugh at us, your fathers and masters called each other brothers and soulmates. If they knew that after all these years you’ve finally gathered, only to act like this, I wonder if they would regret entrusting everything to you."
As soon as these words were spoken, the aggressive tension in the room finally weakened.
Eventually, Xu Qiuchi, assessing the situation, was the first to offer a truce.
"Very well. It is rare for everyone to be so well-represented today; it saves us a great deal of trouble. Since we are all on this boat, we are in the same boat. We might as well take this opportunity to ask each other clearly, lest there be more disputes in the future without a chance for a proper confrontation."
Hearing this, Teng Hu said unceremoniously, "Since you are being so sincere, why don't you first bring out what Qiu Yan left for you?"
Xu Qiuchi’s eyes flickered, and he actually pulled something from his person.
It was a bamboo tube with hooks at both ends, looking like a quiver but much shorter. The moment it was placed on the table, Teng Hu snatched it away.
The cord bindings and wax seal had already been opened. Inside was a roll of palm-sized vine-bark paper. The handwriting on it was blurred, written with something unknown, looking like a rough draft hastily copied by a stone carver.
After turning the item over and over, Teng Hu’s thin brows knitted into a tight knot, and he immediately challenged him.
"What is this? Where are the military records?"
"You can consider this the military record you speak of, just a version that didn't make it into the official registry in time," Xu Qiuchi spoke leisurely, his expression quite candid. "I originally intended to give this to my elder brother. Since you are in such a hurry, there is no harm in letting you see it. This is a manuscript recorded by a messenger soldier under the command of the Black Moon General. It was meant to be sent out, but by a twist of fate, only these fragments remain. Someone picked them up and kept them, and eventually, they fell into my hands."
As he reached this point, he seemed to recall something, and a somewhat cynical smile appeared on his face.
Qiu Ling paid no mind to his expression. He quickly picked up the stack of vine-bark paper, examined it carefully, and said, "Half of this seems to be missing, but the handwriting was indeed not intentionally destroyed. Campaign conditions were harsh; during forced marches, they often couldn't set up camp for days. Records during special periods were mostly made with lead styluses instead of ink, temporarily stored in message tubes carried on the person. Once they reached a relatively safe place, the contents would be transcribed into military reports. Unfortunately, while this type of writing was convenient, it doesn't preserve well on paper or wood; friction or water makes it blur easily."
Seeing the two brothers "singing in harmony," Teng Hu’s thin brows shot up, his voice full of suspicion.
"The gold wax on this military report has been destroyed. How do I know the contents aren't your own handiwork? If you have no intention of being honest, just say so. Don't muddy the waters here."
"If I truly wanted to mislead you, I wouldn't have brought this," Xu Qiuchi took a sip of tea, his face still wearing that half-smile, though his voice turned cold. "When the Black Moon was struck from the records, all accounts of the Battle of Juchao vanished without a trace. Not a single word can be found even through official channels. What makes you think the Qiu family would secretly keep records containing text just to wait for someone like you to settle old scores one day?"
As soon as Xu Qiuchi said this, a dead silence fell over the cabin. Qin Jiuya couldn't help but begin to ponder.
From Teng Hu’s reaction, Zuo Ci likely hadn't told him the details of the Battle of Juchao.
Setting aside whether Xu Qiuchi was merely attacking Teng Hu’s resolve, thinking about it calmly, his logic made sense. As the commander of the Black Moon, Qiu Yan was certainly in the thick of it, the most informed of the informed. The best way to keep a secret was to bury it deep in one's heart, not leave written records. And did this also indirectly suggest that the secret formula was not only related to that battle but also to the disappearance of the Black Moon? If such "evidence" truly existed, the fate of the Black Moon after Juchao might not have been so.
While she was thinking, Teng Hu refused to let it go easily.
"I know your kind. You don't wake early without profit, and you don't work late without a reason. If you didn't know about the past, why would you go to such lengths to come to this island for an appointment based on an ambiguous secret letter?" The other man curled his lips in a fake smile, his voice dropping low. "What? Do you want that secret formula too?"
What was bound to come had arrived.
In fact, before Teng Hu had tested Xu Qiuchi, Qin Jiuya had more or less guessed the reason for the latter's repeated interference in the formula—it likely had to do with the ailing Qiu Yan.
However, Teng Hu didn't know this, and it was absolutely not the right time to mention it.
Xu Qiuchi’s words just now sounded a bit reckless and absurd, but they were actually quite clever, using a diversion to hide his true purpose. But Teng Hu was no pushover either; he had pierced through it instantly.
Xu Qiuchi’s expression changed. But having been tempered in the social arena, he quickly adjusted his state.
"Mister Teng Hu speaks of the secret formula as if he has no guard at all. It’s just that I might know a bit more about the history of this object, so I must maintain a degree of wariness." After saying this, Xu Qiuchi turned to the last page of the contents in the tube, pointing to the faint lead marks. "You heard what my brother said. But precisely because lead powder rubs off easily, the remaining half isn't entirely useless. These notes were sealed in the tube for a long time. I carefully organized the lead traces transferred to the back of the last page and still found some key words. First, the fall of Juchao was not entirely due to the joint siege of the various armies; there was also a flood. Second, a terrifying plague occurred in Juchao at that time. This plague was covered up by the epidemic in Yuzhou after the war. Neither the court nor the common people mention it; they only know that everything was caused by the chaos of war, unaware that Juchao once suffered a plague."
Hearing this, Teng Hu took the remaining notes back into his hand and brought them to a nearby candle to examine them closely.
Having finally shut the fox's mouth, Qiu Ling spoke up with a question of his own.
"So is this why you misused Father’s seal, rearranged the city's water defenses, and prohibited refugees from the direction of Juchao from entering Jiugao City?"
"The lesson of the Black Moon was too painful. Without knowing the full picture, I had to take precautions." Xu Qiuchi didn't shy away from any of it, admitting it on the spot. "Not only that, I have always been wary of the Su family. Back then, the Su family provided medicinal materials for treating the plague as civilian merchants. Su Lin might not know the full truth, but it’s impossible he heard nothing. Does Brother intend to hold me accountable for this?"
When Xu Qiuchi produced that item, Qin Jiuya had already harbored doubts. Qiu Yan had kept this thing sealed for over twenty years; why would he suddenly give it to Xu Qiuchi without telling him more? And reaching into city defense matters was a major affair; even if Xu Qiuchi had the inclination, with Qiu Yan’s decisive and hands-on nature, he would never have let him touch it.
So there was only one possibility: when Xu Qiuchi did these things, Qiu Yan’s condition was already poor. Perhaps the reason he found this long-buried tube and went to such lengths to piece together its contents was also related to this.
But she still couldn't understand Qiu Yan’s original intention. If he had given up and only wanted to avoid trouble, then these surviving notes clearly didn't need to be kept. But if Xu Qiuchi wasn't lying and this tube had been intentionally preserved, it meant Qiu Yan intended to keep it. Yet, if he truly wanted a chance to clear the Black Moon’s name in the future, what could these blurred fragments prove?
And for some reason, she had a faint feeling that Qiu Yan might have known the true contents of the military report that failed to be sent...
The Qiu brothers really had no chemistry to speak of; as soon as one set the stage, the other tore it down. Seeing that Qiu Ling was about to say more, Qin Jiuya quickly spoke up at the right time.
"Speaking of which, why did the Second Young Master suspect there was a problem with Second Miss Su’s illness?"
Xu Qiuchi clearly understood Qin Jiuya’s intent. When he spoke again, he reverted to the posture of a lazy, idle young master.
"Perhaps it’s because I drank too much wine during that period and heard some interesting rumors. Not long before the Su family’s incident, a Grand Tutor in the capital, Lu Yuanshan, also sought medicine for his brother, Lu Sihai. And as luck would have it, a murder occurred in his house shortly after. Lu Sihai, the primary suspect, died suddenly soon after." He paused here, his voice becoming somewhat meaningful. "Didn't Brother personally work on that case? Why don't you tell this part?"
The conversation was instantly tossed to Qiu Ling. The latter pondered for a moment, seemingly weighing whether to reveal the details of the investigation, before slowly speaking.
"I did indeed return to Jiugao because I was tracing the Lu Manor case from the capital, simply because the Su Manor case shared many similarities
