Zhuge Town was home to the scholar-merchant Shang Shiyu, who, in a fit of drunken mockery directed at a wealthy man, was beaten to death by the man's house servants. Yu had two sons, the elder Shang Chen and the younger Shang Li, and a daughter, Shang Sanguan, who was sixteen and on the verge of marriage. Her father’s death halted the arrangements. The two elder brothers went to the magistrate to petition for justice, but their efforts yielded nothing after a full year. The family of Sanguan's intended groom sent people to finalize the marriage proposal, but Sanguan refused, stating, "How can a daughter marry when her father’s bones are barely cold? Does his family have no parents?" Hearing this, the suitor’s party withdrew in shame.

The family was consumed by grief and fury over the unredressed wrong. The brothers planned to preserve their father's remains, waiting for a better opportunity to appeal. Shang Sanguan said, "That our father was murdered and the yamen cannot discern right from wrong shows how dark the world is; we will never see another incorruptible official like Bao Zheng. How could we bear to leave Father's bones exposed?" The two elder brothers agreed wholeheartedly and buried their father.

After the funeral rites were concluded, Shang Sanguan fled in the night, her whereabouts unknown. Her aging mother was frantic with worry, afraid to tell her husband’s family, and dared not inform the clan or friends. She secretly urged her two sons to search for their sister, but after six months, their efforts proved fruitless.

Not long after, the wealthy man celebrated his birthday, hiring actors to perform operas. The troupe leader, Sun Chun, arrived with two disciples. One, Wang Cheng, possessed equal looks and a peerless singing voice that drew universal praise. The other disciple, Li Yu, had a delicate, feminine appearance. The wealthy man ordered Li Yu to sing. Li Yu demurred, claiming ignorance, but the man insisted repeatedly. Unable to refuse, Li Yu softly began to sing a common, bawdy ditty mixed with local dialect, which caused the entire hall to erupt in laughter. Sun Chun was mortified and begged for mercy, saying, "Li Yu has only been with me a short time and has barely mastered the craft. Please, Master, do not blame her. Let her serve wine instead; that she excels at."

The wealthy man nodded and immediately ordered Li Yu to pour wine. Li Yu moved gracefully through the crowd, keenly observing everyone's mood and manners, pleasing all who watched. The wealthy man was delighted. When the feast ended and the guests departed, he insisted Li Yu stay the night. Li Yu swept the couch and took off his shoes, serving him with meticulous care. Fueled by wine, the wealthy man spoke lightly and disrespectfully, yet Li Yu met him with a smiling face, never showing anger, enchanting the man until he was utterly captivated.

The wealthy man dismissed all his attendants, keeping Li Yu alone in the room. Once everyone had left, Li Yu securely bolted the doors and windows. The servants, suspecting nothing, went to another room to drink.

A little while later, a faint rattling sound emanated from the bedroom. A servant drew near to investigate, but the room was pitch black and utterly silent. Just as he was about to leave, the sound started again—like a heavy object hanging from a beam, the rope snapping, followed by a loud shout demanding an explanation. There was no reply from within. The servants were greatly alarmed. They joined forces and kicked the door open, only to find their master cleaved in two, clearly dead; Li Yu was also hanging, the rope broken, causing her body to fall to the floor, a deep bruise visible around her neck.

Everyone was horrified. Messengers rushed about, utterly bewildered as to who the killer could be. They moved Li Yu's body to the courtyard and noticed that her shoes and socks felt light, as if her feet were absent. Upon unwrapping them, they discovered Li Yu had tiny, hooked feet—she was a woman. The astonishment grew. They summoned Sun Chun and sternly interrogated him. Sun Chun was terrified, unable to formulate a defense, repeating only, "Li Yu joined my troupe last month and volunteered for the birthday performance; I truly do not know her background."

Seeing that Li Yu was dressed in mourning attire, they suspected assassins from the Shang family. They ordered two men to guard the corpse. Even in death, Li Yu’s features were lifelike; when the guards touched her, her limbs felt warm and soft. Lust overcame the two men, and they intended to violate the body. One lifted the corpse, preparing to strip her clothes, when suddenly his head received a heavy blow from behind, blood gushing out, and he died instantly. The other cried out in shock. When the other servants rushed in and learned what had happened, they began speculating that "it must be the vengeful spirit of Li Yu." They treated her body with reverence, and only then did they report the murder to the magistrate.

The county magistrate summoned the brothers Shang Chen and Shang Li for questioning. Both brothers claimed, "We know nothing. Our sister left home half a year ago, and we still have no word of her." The magistrate ordered them to identify the body, and they confirmed that Li Yu was indeed Shang Sanguan. The magistrate marveled privately and issued his final judgment: the matter was closed and would not be pursued further. The Shang brothers took their sister's body for burial, and the wealthy man’s family was forbidden from seeking vengeance.