Lai is chief constable of Heyang County. He tries to steal jeweler Su Yu’s phoenix-patterned bracelet whenSu is sleeping. Awakened, Su bites off Lai’s thumb. During the fight, the greedy Lai kills the jeweler, and bribes County Magistrate Jia with the bracelet to cover up his crime. The thief frames the inn owner, Liu Song, for the murder, who pleads not guilty but is detained. Liu’s daughter, Shaoying, stops Yan Tianmingwhen he is on his way to take his post as magistrate of the prefecture of Heyang and presents her case. As an upright official, Yan decides to reopen the case. Learning the news and fearing the consequences, Jiaand Lai force the inn owner to plead guilty and vow never to change his testimonial; otherwise, they will kill his daughter.
Jia gives the bracelet to Yan’s wife, the cousin of Jia and daughter of the Minister of
Justice. At Jia’s request, Yan’s wife sneaks false evidence into the case files behind Yan’s back. As a result, Yan has Liuexecuted, and Liu’s wife dies of grief and indignation. The next morning, Liu’s daughter barges into the court and slams her head against the wall in protest against the unfair trial. Her blood splashes onto Yan’s black gauze cap. Yan is moved by the powerful gesture and decides to look deeper into the case. Yan orders the autopsy of Su’s body, and, having found and examined the finger in the mouth of the corpse, he realizes that he executed the wrong man. Yan orders the execution of the true criminal, Lai, and then commits suicide to compensate for his miscarriage of justice.