Zhang Laifu had saved Li Yunsheng's life, and Li Yunsheng felt that if he did not share the truth now, his conscience would not rest easy.
"Ever since childhood, I aspired to study medicine, and I especially wanted to study modern medicine. I have researched modern medicine deeply as well. Entering the Zhuyou branch was purely by accident, but within this guild, I discovered many valuable medical concepts.
"Brother Laifu, you are from the Outer Prefecture. If you have some knowledge of immunology, you should know that the vast majority of pathogens a person encounters in their lifetime are cleared by the human immune system itself; pathogens eliminated entirely through medication make up only a tiny fraction.
"The Zhuyou branch utilizes precisely this biological trait, curing illnesses by enhancing the human body's own functions. It has deep ties to Outer Prefecture medicine."
Zhang Laifu did not understand medicine, but he could grasp the underlying principle. "In other words, when you cured the yin energy in my body earlier, you actually mobilized my own physical functions to expel it?"
"Not merely expel, but control and convert as well. Yin energy is a toxin with very clear chemical components and properties. The process of control and conversion requires certain specific conditions..." Li Yunsheng began writing out equations as he spoke.
Zhang Laifu feigned rapt attention, nodding from time to time. The dignity of higher education was paramount, but a man with dignity could not necessarily understand chemical equations.
"Brother Yunsheng, I understand everything you said before. But what about the watchman? You pulled a worm out of his gum. What does that have to do with the immune system?"
Li Yunsheng first corrected a conceptual error. "Introducing the essence of the Zhuyou branch from the perspective of immunology does not mean Zhuyou can only mobilize the immune system's defenses. Zhuyou mobilizes the functions of the entire body.
"The treatment back then consisted of three steps. In the first step, I used an incantation to strengthen the watchman's bodily functions, first neutralizing the resentment toxin on the worm. Once stripped of its resentment toxin, the worm lost its special abilities and became an ordinary worm.
"In the second step, I used talisman paper to stimulate the watchman's gums, causing them to rapidly contract in a short time and squeeze out the neutralized worm. This follows the exact same principle as when I had you grip the talisman paper to run like the wind—both are the result of mobilizing one's own bodily functions."
Zhang Laifu had personally experienced the talisman paper's effects, so Li Yunsheng's explanation was easy to grasp.
Yet there was another detail that Zhang Laifu considered crucial. "When you treated the watchman, you mentioned paper ingots and candles. Did he really go burn paper ingots afterward? Was that to appease the ghost's wrath?"
"I did indeed tell the watchman to go to the ash pit to burn candles and paper ingots, but not to appease a ghost's wrath. The police station cleared the corpses from the ash pit long ago, and the ghost isn't there anyway.
"Burning paper ingots and candles was the third step of the treatment—it wasn't directed at the ghost, but at the watchman.
"The watchman's temperament is different from yours; he lacks confidence in himself and easily falls prey to self-doubt.
"Resentment toxin is also a toxin with known components. Although most of it was neutralized during the treatment, a fraction remained. If the watchman believed he hadn't been cured, the lingering resentment toxin would likely flare up again.
"Having him burn paper ingots and candles reinforced the conviction that he was completely cured. It was an important strategy to help him clear the remaining toxin, akin to what Outer Prefecture medicine calls a placebo."
"In other words, you have no way to deal with ghosts at all?"
Li Yunsheng nodded. "It isn't that I don't want to help you; I truly have no means to do so. To deal with ghosts, one genuinely must rely on Heavenly Masters. That is what their trade does."
"Lao Yu from Hunlong Stronghold was a Heavenly Master. He went there, and he was blown into fifty or sixty pieces."
"Fifty or sixty?" Li Yunsheng was a meticulous man. "Brother Laifu, did you count them carefully?"
Zhang Laifu shook his head. "Just an estimate."
Li Yunsheng still found it incredible. "A Heavenly Master dealing with a ghost ought to be effortless. For this ghost to turn the tables and kill a Heavenly Master, his origins must be extraordinary. Do you know his name?"
"He's called Lao Duozi. He claims he steered boats for the Lin family."
"That makes it hard to tell. Plenty of people who take the helm on boats are called Lao Duozi. The Lin family has many boats, and helmsmen thrive in Heishakou. It might be hard to turn up any leads right away."
Li Yunsheng blinked in surprise. "There is a specialized craft just for helmsmen?"
"There is! The pillar of the Lin family, Eldest Young Master Lin Shaoming—a fifth-layer craftsman and venue-suppressing powerhouse—he's a helmsman!"
Zhang Laifu shook his head. "No, Lao Duozi isn't a helmsman. What was he again...?"
After thinking for a good while, Zhang Laifu remembered what Lao Yu had said. "He's a drum-maker. This drum was given to me by him."
"A drum-maker?" Li Yunsheng took the battered drum from Zhang Laifu's hands and inspected it closely. "That changes things. As the saying goes: three years to train a carpenter, five years and still no drum-maker.
"The drum-maker's craft is difficult to learn, and its skills are mostly passed down from father to son rather than taught to outside apprentices. That will make him much easier to track down. I can look into it for you; not many drum-makers could have come out of Heishakou..."
"By the time you find anything, I'll probably have settled things with him." When Zhang Laifu said "settled things," his expression was exceptionally calm.
"Brother Laifu, you've already escaped from that old residence twice. Why must you go back? Do you really need that job so badly?" Li Yunsheng found it difficult to understand.
The job did not matter; what mattered was the bowl. He had to get it back.
Yet as things stood, Li Yunsheng could not help, ordinary Heavenly Masters were useless, and high-level Heavenly Masters were impossible to find. What other way was there?
Actually, Lao Yu had not been entirely useless either. Hadn't he left behind a mark?
Zhang Laifu picked up a brush and paper from the desk and, drawing from memory, sketched the mark Lao Yu had left behind. "Brother Li, take a look. What is this mark used for?"
His drawing was somewhat crude. Li Yunsheng studied it for a long while before finally discerning its general shape. "This is the character for 'skeleton,' written in seal script. It should be the Fourfold Bone-Breaking Curse used by Heavenly Masters."
"What is the Fourfold Bone-Breaking Curse?"
Li Yunsheng first clarified, "I have studied some of the Heavenly Masters' talisman spells, but I cannot use any of them. There are boundaries between guilds; none may cross them.
"The Bone-Breaking Curse is one of the talisman spells commonly used by Heavenly Masters. Its purpose is to destroy a ghost's skeletal remains. Those remains are the ghost's final link to this world; once destroyed, the ghost dissipates as well.
"Heavenly Masters often use the Bone-Breaking Curse to eliminate ghosts. If you saw a Heavenly Master invoke it, that proves he had already located the remains."
Zhang Laifu could not help but admire him. "Lao Yu truly had genuine ability."
During their fight, Lao Yu had been at an absolute disadvantage, completely powerless to retaliate, and severely wounded to boot. To divine the location of the bones under such circumstances—no wonder his nickname was Yu the Calculator.
Li Yunsheng looked closely at the talisman spell Zhang Laifu had drawn again, though he could not say with absolute certainty. "This drawing is incomplete, so I cannot be entirely sure it's the Bone-Breaking Curse."
Recalling Lao Yu's condition at the time, Zhang Laifu also had some doubts. "He wrote this talisman on the spot. If it's a common talisman spell, why wouldn't he keep a few on hand?"
Li Yunsheng shook his head. "The Bone-Breaking Curse cannot be kept on hand. This talisman can bore through the earth and shatter coffins; it can even bore through stone in a great tomb. A talisman spell of such immense power must be written with the Heavenly Master's blood and used immediately. Once the blood dries, the talisman loses its efficacy."
Written and used on the spot?
Zhang Laifu had originally thought about finding a Heavenly Master to buy a couple of talismans from, but it seemed that was out of the question too.
Even so, Lao Yu leaving the talisman on the ground proved he had pinpointed the location of the bones.
Though Zhang Laifu did not possess the Bone-Breaking Curse, if he dug up the skeletal remains and destroyed them, wouldn't that achieve the exact same result?
"Brother Yunsheng, Lao Duozi knows that old residence inside and out. He must have stayed there for a very long time. He surely knows where his bones are, so wouldn't he guard them fiercely?"
Li Yunsheng thought it over and gave a slight shake of his head. "Most ghosts do not know where their bones are. Their perception undergoes a fundamental change; even if you placed the bones right in front of them, they wouldn't be able to recognize them.
"If this Lao Duozi has lingered in the old residence for many years, that suggests he is very likely bound by his skeletal remains, unable to leave. If he truly could find his own bones, he would have taken them and left that compound long ago."
Zhang Laifu's eyes lit up. "Brother Li, do you have a way to destroy skeletal remains?"
Li Yunsheng emphasized once more, "I am a doctor. I only do things to save people.
"Destroying corpses and wiping out traces is something I do only occasionally. Sometimes, to prevent the spread of disease, one has no choice."
Zhang Laifu nodded repeatedly. "Brother Yunsheng is a good man!"
Li Yunsheng handed Zhang Laifu a bottle of potion.
"Pour this bottle of liquid over the bones, and within ten minutes, they will dissolve completely."
Seeing that the bottle was not very large, Zhang Laifu worried the dosage might not be enough.
Li Yunsheng was full of confidence. "Even if there were over a dozen people, this single bottle would suffice. I say this not because of anything I've actually done, but purely from a scientific calculation of the dosage."
Zhang Laifu took the potion and nodded once more. "Brother Yunsheng truly is a good man."
Chapter 30