When you Marry a Detective in a Flash Please Pretend you Don’t Know Him in Public

Immediately after the wedding, a homicide interrupts their new life. A highly decomposed female body is discovered on Qingluan Mountain, and Wen Qingli is called to the scene to perform a forensic facial reconstruction on the victim. Using craniofacial landmark techniques, she recreates the victim's appearance within an hour, revealing that the deceased is Lin Weiwei, a graduate student at Lincheng University. Lu Zheng investigates and discovers that Lin Weiwei had been supported financially for ten years by Ji Chuan, a man from her hometown who worked multiple jobs to fund her education. Ji Chuan voluntarily surrenders, confessing to beating Lin Weiwei to unconsciousness after she smashed his deceased mother's urn and cruelly rejected him. However, the forensic evidence shows Lin Weiwei died of manual strangulation, indicating someone else killed her after Ji Chuan fled.

During the investigation, Lu Zheng learns about Professor Gu Huaiyuan, Lin Weiwei's academic advisor, and his wife Professor Su, whose relationship appears strained following two miscarriages. Wen Qingli provides Lu Zheng with information about the professor's marital troubles, and the two begin working closely together on the case. They sneak into Professor Gu's office late at night to search for evidence, where Wen Qingli discovers a broken fingernail wedged in a cabinet door. DNA testing confirms the nail belongs to Lin Weiwei, and skin cells found beneath it match Professor Gu Huaiyuan.

Professor Gu is arrested and confesses to murdering Lin Weiwei, claiming she deserved death for causing his wife's miscarriages through harassment and hired thugs. He admits to strangling her in his office after she threatened to expose their affair. However, Lu Zheng remains suspicious about inconsistencies in the timeline and Lin Weiwei's motivations. Meanwhile, Wen Qingli and Lu Zheng's relationship deepens as they move in together. She discovers messages from his high school crush, Bai Chuxue, who is returning to China for their school anniversary. Lu Zheng transfers money to Wen Qingli and asks her to help select clothes for him, signaling a shift from their arrangement toward a more genuine partnership.

As the case progresses, Lu Zheng begins to question whether Professor Gu is the true killer or merely a pawn in a more complex web of manipulation involving Lin Weiwei's relationships with both Ji Chuan and Gu Huaiyuan. The story follows the evolving dynamic between Wen Qingli and Lu Zheng as they navigate their marriage, professional collaboration, and the unresolved questions surrounding Lin Weiwei's death.