The Golden Hairpin

"Actually, it's nothing much, is it? You knew from the start that the candle wouldn't burn for long before exploding, scattering the crowd, and the bit of mercury vapor wouldn't be enough to kill anyone." Huang Zixiao shook her head. "But even with your meticulous planning, you slipped up on the wax blocks. It took the Jianfu Temple so long to gather the wax, yet you managed to collect enough to make such a large candle in just a few days. I ask you, where did you get all that wax? You claimed it was saved up over the years, but if you had that much stored, would the temple have needed to purchase it from all over the country? The truth is, you never used that much wax to begin with—because the candle was hollow from the start! Most of the wax blocks sent by the temple were left unused!"

Seeing Lü Zhiyuan's ashen face and inability to defend himself, Zhou Ziqin quickly asked, "Chonggu, I have a question! Though those days were already oppressive, with thunderstorms looming, what if the storm hadn't come? What was his backup plan?"

"Even if the iron wire hadn't drawn the lightning strike, the wax below was mixed with black oil and sulfur. A little longer, and the entire candle would still have exploded. The shattered wax would have burned completely, and Wei Ximin, hidden inside and already coated in flammable material, would still have been burned alive! He could have claimed the candle malfunctioned, exploding and accidentally harming someone. It just wouldn’t have been as dramatic as divine retribution via lightning."

Cui Chuncan frowned. "Indeed... Wei Ximin was inside the candle, and just as Master Liaozhen spoke of divine retribution, thunder roared, the iron wire drew the lightning, and the candle exploded—as if heaven itself was aiding the act. In the chaos, everyone would assume the fallen man was someone near the candle who got burned. Who would notice where he came from in the crowded panic?"

Zhou Ziqin, still puzzled, asked, "Then why would Wei Ximin willingly stay inside the candle? He was rolling on the ground, howling in agony. Why would a living person agree to hide inside a candle?""Lingling Xiang, have you forgotten? After Qian Guansuo heard Lü Zhiyuan mention he had premium Lingling Xiang, he bought some to thank Changpu, the cook at the princess's residence. As a servant, Changpu naturally had to present such valuable items to the princess for inspection first, according to the household rules. However, the princess had not yet borne children after marriage—why would she use something harmful to pregnancy? Meanwhile, Wei Ximin was both greedy and suffered from chronic headaches, making Lingling Xiang perfect for him. So, he took it for himself. Using one liang per day, by the seventh day, the incense was gone. He went to demand more from Changpu, causing a scene before extorting Qian Guansuo, who then took him to Lü Zhiyuan’s shop—the night before the Jianfu Temple festival. That night, Wei Ximin never returned. And this man, widely known to disdain gods and buddhas, suddenly appeared at the temple the next day, unseen by anyone beforehand, only to be engulfed in flames, screaming to his death." Huang Zixiang stared at Lü Zhiyuan and continued slowly, "Lü Zhiyuan had calculated everything: first, the princess’s household rule that all valuable items must be presented to the master; second, using Qian Guansuo to recommend his Lingling Xiang; third, estimating the dosage for a headache sufferer, ensuring Wei Ximin would return for more after a few days. Everything went as planned—Wei Ximin walked into the trap and vanished from his shop. That night, I suspect Lü used doctored Lingling Xiang to keep Wei Ximin unconscious until he awoke in flames."

All eyes turned to Lü Zhiyuan, watching the gaunt old man kneel motionless before the court, like a withered tree root long dead, etched with the harsh lines of time and hardship.

Huang Zixiang pressed on firmly, "And Sun Laizi’s death is also tied to you."

"No, Eunuch Yang, you might be mistaken about Sun Laizi’s case," Zhang Xingying said quietly, observing the silent Lü Zhiyuan. "Sun Laizi died at noon… Both A-Di and I went there but found no chance to act. At that time, we didn’t see Lü… Old Lü in Daning Ward, and many later confirmed he was at his shop in the West Market making candles. I don’t believe he could’ve killed Sun Laizi."

"He didn’t need to be there. From the moment he arranged for repairs to Sun Laizi’s house, Sun was doomed." Huang Zixiang signaled Zhou Ziqin to display the iron plaque they had pried from Sun Laizi’s door. "Above Sun Laizi’s front door was a fashionable iron plaque. The craftsmen who reinforced his house installed a brand-new one, its paint still bright. But after the incident, the paint had completely worn off."

"This iron plaque… was Qian Guansuo’s doing!" Cui Chunhan pointed at the cowering Qian Guansuo once more.

The crowd’s attention shifted back to Qian Guansuo.The lifeless expression on Qian Guansuo's face suddenly changed as he looked at Huang Zixiao and then at Lü Zhiyuan. His previously dull eyes widened in shock. Summoning an unexpected burst of strength, he struggled up from the ground and cried out hoarsely, "Wronged... I've been wronged! This commoner didn’t kill anyone! The iron plaque was... was forged at Liu’s Blacksmith Shop. After I brought it back, it was just left there—I only glanced at it once!"

Zhou Ziqin couldn’t contain his impatience and grabbed Huang Zixiao’s arm, asking, "What do you think is the connection between this small iron plaque and Sun Laizi’s death?"

Huang Zixiao countered, "Do you remember what the neighborhood head of Daning Lane told us? When Boss Qian broke open Sun Laizi’s door, a burst of black smoke rushed out, and everyone thought it was the vengeful ghost of Dicui?"

"Yes, the neighborhood head mentioned that," Zhou Ziqin replied, glancing at Zhang Xingying before scratching his head in confusion. "But the problem is, Dicui isn’t dead—how could there be any vengeful ghost or ominous aura?"

"Because someone burned something on the door. When the door was forced open, the ashes were disturbed, and since the room had been sealed, the sudden rush of air caused the black soot to scatter, creating what people called the black 'ominous aura.'" Huang Zixiao pointed to the charred and peeling lacquer on the iron plaque. "But there were no signs of fire inside the room. The only ashes were hidden inside this hollow iron plaque. So, the key to Sun Laizi’s death lies here."

"After Sun Laizi’s body was discovered, the Dali Temple immediately sealed off the room. No one could have accessed the plaque afterward, so the only possibility is that between the night the doors and windows were reinforced and noon the next day, someone burned something inside this plaque. And I’m certain that substance was linglingxiang —because when we went to investigate that night, Wang Dufu, the son of Minister Wang, escorted us and detected traces of linglingxiang lingering in the room. He’s a renowned incense connoisseur in the capital—he wouldn’t mistake it. I also believe this linglingxiang was the same kind used to drug Wei Ximin, which is why Sun Laizi remained motionless even after being stabbed twice before dying."

Cui Chunzhan quickly asked, "Then how did Lü Zhiyuan sneak into the sealed room to kill Sun Laizi? Unless... he also knew about the sewer passage?"

"This case has nothing to do with the sewers. If the killer had entered through the sewers, there would have been traces inside the room. Even if the crowd following Qian Guansuo had trampled over them, the floor wouldn’t have remained so undisturbed. Besides, Lü Zhiyuan was busy in his shop at the time—when would he have had the chance to crawl through the sewers?" Huang Zixiao gestured for Zhou Ziqin to lift the perforated patterns on the iron plaque. "As you can see, among the residual ashes inside, there are two streaks where fingers wiped something away. Before we examined the plaque, who would have noticed this object buried among Sun Laizi’s wall of charms and portraits? No one would have even thought there was anything hidden inside. I believe the only person who would have reached inside to take something out was the killer. So, what exactly did the killer remove from here?"She pointed to the two remaining marks in the incense ashes inside and said, "This is a larger circular trace. If this object were circular, judging by its diameter, it would be absolutely impossible to extract it from the bizarre, irregular perforations of the iron plaque. However, if it were a flat disc, the murderer could barely insert a finger to shift it from the very bottom and remove it through this long, cloud-shaped gap below. But the murderer didn’t take it out that way—they took it from above. Yet the only opening up there is barely wide enough for a single finger to pass through. What kind of large circle could be extracted from such a tiny space?"

The crowd couldn’t help but stare at the small hole, lost in thought. The hall fell silent for a moment, with only Zhang Xingying standing there, gazing at Dicui’s father as if he were a stranger. Lü Zhiyuan stood dazed, neither speaking nor moving, as though everything Huang Zitang had said held no relevance to him.

After a brief silence, Li Shubai spoke slowly, "It’s a spring clip."

"Yes, the kind used in crossbows. When scraped against the ash, it leaves a larger circular impression. But no matter how small the opening, as long as you twist it a few times, it can be effortlessly removed." Huang Zitang turned her gaze back to Lü Zhiyuan and added with a sigh, "And Old Lü here was once conscripted into the military—specifically, the crossbow unit."

"Are you saying Lü Zhiyuan installed a crossbow inside this?" Zhou Ziqin was stunned.

"No, just two spring clips would suffice." Huang Zitang pointed at the iron plaque. "The outer layer was coated with phosphorus powder, behind which was placed lingling incense. Behind the incense, there were wax-sealed spring clips, each holding two thin, poisoned iron plates."

"I remember now! Sun Laizi’s festering sores forced him to sleep in that sideways position. And Old Lü, having served as a crossbowman for years, could easily adjust the clips based on the angle between the gate and the bed, sealing them with wax to target the only space left on that cramped bed—where a man always slept in that exact posture!" Zhou Ziqin suddenly understood. "At noon—or even earlier, as long as the sunlight was intense enough—the heat on the iron plaque would ignite the phosphorus, setting the lingling incense alight. This sedative incense would make Sun Laizi drowsy, and his bed faced directly toward the gate and the iron plaque above it. Once the incense burned out, the fire inside the plaque would melt the wax sealing the clips in an instant. The released springs would then shoot the iron plates at a slightly downward angle, piercing Sun Laizi’s body. The incense had already kept Wei Ximin asleep all night, and Sun Laizi, still groggy from the journey, likely felt nothing before he died!"