When Li Yuangui followed the Emperor up to the street-facing tower of Wanshan Temple, he saw a large screen placed in the chamber, with a couch and desk arranged before it. Two gilt wine vessels on the desk caught his eye with their dazzling gleam.
Empress Zhangsun stayed behind the screen. After exchanging greetings and performing proper courtesies, the Empress commanded: “Lady Wei to report again to Your Majesty the hidden truth of the Linfen County Princess case.” Li Yuangui’s heart pounded as he knelt on the mat, listening intently to Wei Shubin’s analysis from behind the screen.
When she concluded that the true murderer of Li Wanxi was Yang Buyao, who had just given birth to a son for the Emperor, Li Yuangui suddenly raised his head and noticed the Emperor indeed looked somewhat uncomfortable, though he showed no other reaction. Wei Shubin then explained the peculiarities in the County Princess’s farewell letter and her deductions. Li Yuangui found himself nodding in agreement with this part, privately commending “Shubin has grown increasingly clever.”
After the long explanation, the Emperor pondered for a while before asking him, “What does Fourteenth Brother think?”
Li Yuangui considered before responding as diplomatically as possible: “The key evidence in Lady Wei’s reasoning is this golden vessel used for poisoning ten years ago. Her conclusion that it belonged to the Princess Consort of Hailing seems somewhat tenuous given the available evidence. The two vessels being so similar must certainly share the same origin—”
He suddenly remembered something and stood up to take the new vessel that had appeared just yesterday. Turning it over to examine the engravings on the bottom, he exclaimed, “Indeed, it has the same inscription!”
“What inscription?” the Emperor asked.
Li Yuangui showed his brother where a line of patterns distinct from the surrounding cloud motifs appeared on the bottom—several circles linked together with occasional curved lines and dots branching out. He picked up the old vessel to compare, finding an identical inscription on its bottom. Though there were slight differences in position and size due to hand engraving, the content was unmistakably the same.
“This is the tribal script commonly used by merchant Sogdians,” the Emperor surprisingly recognized, “quite common in the Western Regions. What does it say?”
Li Yuangui felt somewhat impressed by his second brother and replied: “One of my maids can read Sogdian script. She says it’s the craftsman’s mark, meaning ‘Craftsman Pantuo made a pair of golden vessels weighing thirty staters in Fuyi City’—stater being a unit of weight.”
“A pair?” The Emperor looked at the old and new vessels and smiled. “They truly are a pair, completed after ten years apart—quite remarkable. Though the craftsman forgot to engrave one more line—”
He tapped the double-chambered vessel’s body, producing a clear ring, “—’ Specially made for poisoning the Heavenly Khagan.'”
It was meant as a joke, but no one in the room, including the women behind the screen, could laugh. Yesterday’s fake poison in the new vessel was one thing, but this old vessel had truly almost taken Li Shimin’s life ten years ago, making him vomit blood. According to the court physicians like Wu Jingxian, though they had saved him, his stomach, spleen, and liver were severely damaged. He still suffers from the effects today, with summer heat often triggering respiratory issues related to that incident.
“The old case from ten years ago is difficult to investigate now. But it should be easy to trace where this new vessel came from, right?” the Emperor asked Li Yuangui again. “You were deeply involved in the Prince matter. Who gave this vessel to that young man?”
Though Li Yuangui had an ominous feeling, he had to answer: “It was Kang Sumi.”
The Emperor then summoned Kang Sumi to come upstairs and report. Today’s polo match had drawn crowds in Chang’an, and envoys from various countries had come to Xixiang Ward to watch. Kang Sumi, holding the fifth-rank title of Sabao and being closely connected to this matter, had naturally arrived early.
When the imperial brothers crossed the street to Wanshan Temple, the polo match was nearly over. The Prince had struggled to score just two points, while Yang Xinzhi had scored nine—one more goal would end the match. After hearing reports from palace servants, the Emperor had ordered his attendants to detain Kang Sumi and others involved in the case, preventing them from leaving.
Li Yuangui waited upstairs with his brother and sister-in-law for a short while before the old Sogdian merchant climbed up, his large belly preceding him as he kowtowed to the Emperor. He nodded in greeting to Li Yuangui, his bearded face still wearing a happy smile, showing no shame.
At the Emperor’s glance, Li Yuangui took up the new golden vessel and held it before Kang Sumi, asking him “where this double-chambered vessel came from.” The old merchant replied naturally: “This was made by craftsmen in old Kang’s household, quite some years ago. When this matter came up, I thought long and hard before remembering it, then spent ages digging it out to use.”
Quite some years ago… Li Yuangui pressed: “Exactly when was it made? Where was it made?”
Kang Sumi scratched his head in thought, then took the vessel to examine its bottom, finally exclaiming with a smile of recognition: “Ah yes, it was made in Fuyi City. Must be twenty years ago, if not more. I remember, back then the empire wasn’t in chaos yet, and old Kang was still young, doing business with my brothers in Tuyuhun. The Murong family was in turmoil though, with fathers, sons, and brothers all killing each other. Someone came to us with a sample, asking us to make these wine vessels. Old Kang thought it was interesting, had the craftsmen make some improvements, and made an extra pair to keep. Later…”
“Later, you first gave one vessel to someone, ten years ago,” the Emperor cut in coldly from the couch. “To whom?”
The old merchant’s deep-set eyes darted around, glancing at the tarnished old vessel on the desk, his expression growing more cautious:
“Let old Kang think… Right, must be twelve or thirteen years ago, in Chengdu, Shu. Just drinking and chatting with a Tang army general, we both got quite drunk, talking about how Chang’an was in as much chaos as the Murong family in Tuyuhun. Later old Kang sent some gifts over, including one vessel among them, no special meaning, just for fun…”
There must have been a special meaning, Li Yuangui thought—implying “providing your elder brother convenience in royal family conflicts,” an intention worthy of punishment. He leaned forward, suppressing an inexplicable panic, and pressed:
“Which Tang army general received your golden vessel?”
Kang Sumi hesitated, looking between the Emperor and Li Yuangui, before reluctantly admitting:
“It was Prince Consort Chai… old friends, you see, old Kang wasn’t familiar with others…”
A thunderous realization struck Li Yuangui as he collapsed back onto his legs, waves of panic washing over him.
The Emperor’s expression grew severe as he immediately ordered his attendants to “summon Prince Consort Chai.” Without a moment’s delay, Prince Consort, Great General, and Duke of Qiao Chai Shao, who must have been waiting in the temple, arrived upstairs even faster than Kang Sumi had. He entered the chamber and performed his courtesies, his expression calm but slightly puzzled.
Kang Sumi repeated the story of giving him the golden vessel in Shu over a decade ago, confronting him directly. Chai Shao glanced at the old vessel on the desk, his expression changing dramatically:
“What nonsense is this! Old Kang, how dare you spew such baseless accusations! I’ve never seen this vessel! No… I have seen it, Your Majesty knows…”