Episode Summary
The investigation into Song Rou's murder initially focuses on Wei Qizhi, who is believed to be her lover and has a suspicious limp. However, through careful forensic work, Qin Wan uncovers clues that point elsewhere, including paper in the victim's stomach and the strange behavior of the younger brother, Wei Yanzhi. It is ultimately revealed that Wei Yanzhi was Song Rou's true lover and her killer. He murdered her because he was unwilling to abandon his ambitions to elope with her. After his confession and arrest, Yan Chi decides to change his career path to work more closely with Qin Wan.
Spoiler Alert
Coroner's Diary: Episode 5 Spoilers
The investigation into Song Rou's murder takes a sharp turn when the coroner's box is stolen, only to be found abandoned at the entrance of the yamen. Though nothing is missing, Qin Wan detects the lingering scent of a rare and expensive ointment sold only in the capital. Meanwhile, new information surfaces: Wei Qizhi, the eldest son of the Wei family, didn't just injure his leg; his father broke it before imprisoning him at home, after which he vanished. Qin Wan recalls that the person who attacked her that night seemed to have an injured leg, leading Yan Chi to suspect the Wei brothers.
Under questioning, an attendant of the younger brother, Wei Yanzhi, admits that Wei Qizhi was indeed Song Rou's secret lover. He claims the Wei family wished for a marriage, but the prominent Song family refused due to the Wei's lower social standing. Wei Yanzhi says he lied to protect his brother and is placed under house arrest. The priority, however, remains finding Song Rou's head and the murder weapon. Qin Wan makes a strange discovery during the autopsy: scraps of paper in Song Rou's stomach. Why would a woman of her status resort to eating paper?
The plot thickens when Wei Qizhi is caught trying to steal the coroner's box a second time, falling right into a trap set by Yan Chi. Attention then shifts back to Wei Yanzhi, who has conveniently fallen ill. Qin Wan finds his sickness suspicious; despite his cough, he keeps his window open while a charcoal fire burns inside. Searching through the ashes, Qin Wan and Yan Chi are interrupted by news of Wei Qizhi's capture, but Qin Wan wisely instructs Yue Ning to guard the ashes.
During a harsh interrogation by Prefect Huo, Wei Qizhi maintains his innocence. His attendant rushes forward, revealing that Wei Yanzhi is also proficient with his left hand. The real story finally comes out: Wei Qizhi's leg was broken by Duke Song after he falsely confessed to an affair with Song Rou. He only did so because Song Rou tearfully begged him to, admitting she was involved with someone else whose name she couldn't reveal. Fearing for her safety, he took the blame. Qin Wan confirms his innocence by discovering he has a severe allergy to lacquer, an ingredient in the paper Song Rou swallowed, meaning he couldn't have handled it.
With the truth closing in, Wei Yanzhi attempts to flee but is apprehended by Yan Chi. In the ashes Yue Ning guarded, Qin Wan finds the final piece of evidence. After painstakingly reconstructing Song Rou's skull, she determines the fatal wounds match Wei Yanzhi's sword. Cornered, Wei Yanzhi confesses. He reveals that Song Rou wanted them to elope, but he was unwilling to sacrifice his career and future for a life in hiding. After they were intimate one last time, he brutally murdered her. Qin Wan is enraged that he could kill the woman who loved him enough to give up everything.
With the case closed, Qin Wan respectfully restores Song Rou's body, giving her the dignity she deserves. Wei Qizhi visits his unremorseful brother in prison before arranging for Song Rou to be buried in Jingzhou, as her own family would not accept her in their ancestral tomb. Realizing Qin Wan's invaluable skill, Yan Chi sends a message to the capital, cancelling his transfer to the Ministry of War and requesting a new post in the Ministry of Justice, solidifying their partnership.
