Concubine Daijia had secured what she wanted: a silent promise of protection from the Grand Empress Dowager. Yet, she did not become complacent or arrogant. She continued to visit Cining Palace daily, her attitude even more subservient, her work even more meticulous.
When Emperor Kangxi visited to pay his respects, Daijia deliberately made herself scarce, never taking the opportunity to vie for his attention. She made it unequivocally clear: her sole purpose was to serve the Grand Empress Dowager, and she had entirely abandoned the battle for the Emperor's favor.
Though Daijia's initial motive was purely transactional—survival for her crippled son—her dedication was genuine. Over time, the Grand Empress Dowager's hardened heart softened slightly toward the young mother. She began to ask after the Seventh Prince's health and occasionally sent child-rearing supplies to Daijia's quarters.
Initially, Yinreng felt a twinge of jealousy at sharing his great-grandmother's affection. However, his pragmatism quickly won out. He was not the only great-grandson, and he had no right to monopolize her love. Besides, he had far more critical matters to attend to:
Songgotu and Physician Liu had finally returned to the capital.
Their field research had lasted several months. While they hadn't mapped the entire empire, they had extensively surveyed several heavily populated provinces. Because Songgotu carried the Emperor's mandate and acted on behalf of the Crown Prince, local officials had scrambled to cooperate. Prefects and magistrates had aggressively compiled records of cowpox outbreaks in rural villages, handing over the data immediately upon the team's arrival.
As a result, they returned with a literal carriage full of raw medical data.
"Physician Liu, Uncle, you have worked hard. Please rise!" Yinreng greeted them.
Songgotu looked exhausted, clearly wishing to go home and sleep for a week. Physician Liu, however, practically vibrated with manic, scientific energy.
"I am not tired at all, Your Highness!" Liu declared, his eyes burning with excitement. "The survey was a massive success! Based on the filtered data, I can definitively confirm that the pox transmitted from cows to humans results in significantly milder symptoms than the standard human strain. However, it is still lethal in a notable percentage of cases. Therefore, directly exposing a healthy human to an infected cow to build immunity is too dangerous. It would be akin to murder."
Yinreng smirked. "You look entirely too pleased for someone delivering bad news. You discovered something else, didn't you?"
"Yes!" Liu dropped to his knees again, slamming his forehead against the floor in reverence. "Your Highness, the timing of the infection changes everything! The data proves that patients who contracted the disease from the 'pus' of a freshly sick cow suffered severely. However, patients who were infected by coming into contact with the 'dried scabs' of a recovering cow experienced remarkably mild symptoms, with a survival rate exceeding ninety percent!"
Physician Liu looked up, his expression fiercely determined. "Your Highness, I request permission to infect a cow for experimental observation!"
"You want to deliberately infect a cow, nurse it back to health, and harvest its scabs?" Yinreng asked.
"Yes!"
"And what will you do with the scabs once you harvest them?"
Liu froze. The scientific high instantly evaporated. 'Right. What then?' He couldn't just rub them into a human test subject; it was still a theoretical hypothesis. As a physician, his duty was to save lives, not gamble with them.
"I have a methodology," Yinreng supplied smoothly. "We will test it on animals first. Perhaps white... rabbits." He had almost said 'white mice,' but remembered that large-scale laboratory mouse breeding did not exist in the 17th century. Rabbits, however, bred rapidly and were widely available from local farmers.
"If the rabbit trials show significant success and prove the scab theory is safe, we move to human trials," Yinreng continued coldly. "We will use death row inmates from the Ministry of Justice."
Context: In this era, the concept of human rights for condemned criminals was non-existent. Physician Liu saw absolutely no moral conflict in this progression.
"Yes! Rabbits first, then the condemned!" Liu agreed eagerly.
"This requires Imperial Father's explicit approval," Yinreng noted. "If you are not too fatigued, shall we proceed to Qianqing Palace immediately?"
"I am perfectly energized!" Liu scrambled to his feet.
Songgotu opened his mouth to protest his exhaustion, but Yinreng was already walking away.
Resignation: Songgotu sighed and trudged after them.
***
Qianqing Palace.
Yinreng presented Physician Liu's compiled data to Emperor Kangxi. Kangxi read through the reports with growing astonishment. He had assumed Yinreng's "cowpox" idea was just a child's passing curiosity. He had not expected concrete, actionable epidemiological data.
"Physician Liu, how confident are you in this theory?" Kangxi asked sharply.
Liu knelt. "I cannot guarantee success, Your Majesty. However, I believe it is highly viable. Furthermore, even if the vaccine development fails, this controlled experiment will grant us unprecedented knowledge regarding the pathology of smallpox. It will dramatically improve our treatment methods and survival rates for future patients."
Kangxi's expression turned solemn. He and Yinreng had survived smallpox, but he had dozens of other children and relatives who had not. If this experiment could even slightly increase their chances of surviving the inevitable outbreaks, it was worth the risk.
"Approved!" Kangxi declared. "But the experiments cannot take place within the capital."
Logic: If the virus escaped containment, the entire imperial family and the highest-ranking nobles in the empire would be eradicated.
"We will requisition an isolated rural estate," Yinreng proposed, immediately launching into modern quarantine protocols. "Establish a five-mile exclusion zone around the perimeter, heavily guarded by the military. The estate itself will be strictly divided into two zones: an 'Inner Zone' for the infected test subjects and animals, and an 'Outer Zone' for the uninfected medical staff.
"We will construct a decontamination bathhouse exactly on the border between the two zones. Anyone transitioning from the Inner to the Outer Zone must strip completely, burn their clothing, and scrub their entire body—down to every hair follicle. The entire estate must be aggressively sterilized using quicklime and boiling water."
Yinreng turned to Liu. "I have read military reports stating that soldiers sometimes use strong liquor to clean battle wounds to prevent rot."
"That is correct," Liu nodded.
"Therefore, alcohol possesses sterilization properties," Yinreng concluded. "The entire estate should also be frequently washed down with high-proof alcohol. Does Imperial Father agree?"
"Excellent," Kangxi said, deeply impressed by the boy's meticulous logistical planning. "Is there anything else?"
Recognizing this as a test of his administrative foresight, Yinreng continued. "Supply lines must be strictly regulated. Communication should be minimal and handled only by the outer perimeter guards to prevent cross-contamination. Any supplies that enter the Inner Zone must never leave. All biological waste and used materials must be incinerated on-site, and the ashes buried deep underground, far away from any water sources."
Kangxi's eyes shone with pride.
"Finally, regarding the human test subjects," Yinreng added. "I have read the penal codes. Not all death row inmates are irredeemable monsters. Some are victims of circumstance. I propose we offer them a choice and an imperial grace.
"If an inmate volunteers for the trial and survives, we grant them a review of their case. If they were wrongfully convicted, they are pardoned. If they are guilty but acted out of desperation or justifiable circumstances, we cannot pardon the crime, but we can secretly compensate their families with silver. However, if the volunteer is a serial murderer, a rapist, or utterly unrepentant... we simply use them for the trial and execute them afterward."
Internal Monologue: Yinreng's morality was pragmatic. Basic human rights were for humans. Monsters deserved nothing.
Kangxi stared at his son for a long moment before throwing his head back and laughing loudly. He had worried that Yinreng might be too soft-hearted regarding the prisoners. Instead, the boy had delivered a masterclass in imperial leadership: ruthless efficiency balanced perfectly with calculated benevolence.
He pulled Yinreng into a tight embrace. "To have such a Crown Prince is the supreme blessing of the Qing Dynasty!"
Songgotu and Liu hurriedly echoed the praise.
Yinreng, suffocated against Kangxi's robes, internally rolled his eyes.
"It is decided!" Kangxi announced. "I will issue an edict instructing the Ministry of Justice to cooperate fully!"
***
Outside Qianqing Palace, Yinreng dismissed Liu to begin his preparations and pulled Songgotu aside.
"Uncle, Physician Liu is a brilliant doctor, but he is a terrible administrator. I need you to manage the logistics. Liu will control the Inner Zone; you will manage the Outer Zone, the military perimeter, and the supply lines. Your priority is to ensure Liu lacks nothing. You will also personally select the inmates from the Ministry of Justice."
Yinreng signaled his head eunuch, Xiaozhu, who handed Songgotu a heavy wooden lockbox.
"Do not worry about the budget. If you run out, come to me," Yinreng instructed.
Songgotu opened the box and gasped. It was packed with gold ingots and high-denomination silver notes. "Your Highness! The Emperor has already approved the project. The Ministry of Revenue will allocate the funds. Why are you paying for this from your private treasury?"
"Because time is of the essence," Yinreng explained patiently. "The national treasury is depleted from fighting the Revolt of the Three Feudatories and recovering from the recent Beijing earthquake. The Ministry of Revenue will stall, audit, and delay the funding for months. This project cannot wait.
"Furthermore, smallpox terrifies people. If this massive expenditure goes through the official channels of the Ministry of Revenue, it will trigger a vicious debate in the imperial court. Factions will argue that spending state funds on a 'mad medical experiment' is a waste when other provinces need disaster relief. They will try to shut it down. By funding it privately, we bypass the bureaucracy and silence the political opposition."
Songgotu understood the strategy instantly, but his expression turned grave. "Your Highness... do you understand the political risk you are taking by doing this independently?"
Yinreng raised a hand, his eyes cold and unwavering. "I am fully aware of the consequences. Go execute your orders, Uncle."
Songgotu closed his mouth, bowed deeply, and left to begin the work.