My Roommate Is a Detective Episode 16 Recap
> My Roommate Is a Detective Recap
Qiao Chusheng and Lu Yao arrived at the St. George University medical school laboratory to investigate the death of Guan Dailiang. Bai Youning soon joined them, having learned about the case through her extensive network across Shanghai. She urged them to quickly resolve the investigation, as the university's board members were influential tycoons who would exert pressure if the case dragged on, potentially costing Qiao Chusheng his job and Lu Yao his reputation.
Lu Yao, however, casually dismissed these concerns, suggesting he could simply freeload at Qiao Chusheng’s home if he lost his job. Lu Yao meticulously examined the dissection room, noting its single exit and the central dissection table, which would have made any manipulation of the body easily noticeable by students. He also ruled out entry through the windows due to the presence of students.
Meanwhile, Bai Youning efficiently gathered details on Guan Dailiang, revealing he was a local medical doctor, a professor of Infectious Diseases, and recently bereaved of his father. Qiao Chusheng questioned the students present during the class, confirming that no one had entered or exited the classroom during that time, suggesting the body was already in the tank.
A critical piece of information also emerged: Guan Dailiang had been seen entering the laboratory building two days prior and had not been seen leaving since, indicating the killer might be one of the few people who accessed the building during that period. The autopsy report revealed Guan Dailiang’s death occurred between midnight and 4 AM, but the cause remained elusive due to the extensive interference from formalin.
Lu Yao consulted the laboratory’s in-out register and identified three individuals who entered the lab during this timeframe: Guan Maoliang at midnight, Lin Ai at 1 AM, and Liu Yansheng at 2:30 AM. Qiao Chusheng immediately brought them in for questioning. Guan Maoliang, Guan Dailiang’s brother, claimed he was in his own lab and then visited his brother for personal reasons, without any witnesses.
Liu Yansheng, a fellow doctor, denied ever meeting Guan Dailiang, despite Qiao Chusheng's assertion that Guan Dailiang was eccentric and had a sharp tongue, making him unpopular among many. Lin Ai stated she was alone in her lab conducting experiments. All three lacked solid alibis, prompting Qiao Chusheng to dispatch his men to investigate their backgrounds further. Lu Yao returned to the lab where Guan Dailiang’s body was found.
The coroner had previously reported severe corrosion in the victim's oral, nasal, esophageal, and tracheal cavities. Lu Yao’s keen observation led him to discover brown powder residue in the glass tank. He deduced that this powder was a compound formed from the reaction of potassium permanganate and formalin. He explained that formalin, an aqueous solution of formaldehyde, reacting with potassium permanganate, a strong oxidant, would produce a large volume of corrosive gas.
This gas, when forced into the body, would erupt from the mouth, nose, and eyes, creating a terrifying effect of the body coming back to life with wide eyes and an open mouth. This chemical reaction also explained the severe facial and head corrosion. Suddenly, a shadow flickered past the window. Lu Yao, quick on his feet, jumped from the third floor and chased after the fleeing figure, with Bai Youning following closely.
Despite their pursuit, the person managed to escape. Lu Yao then stopped Bai Youning from continuing the chase, stating that he didn't want to lose such a perfect and clean roommate. Their conversation soon turned to the gruesome murder method, with Lu Yao speculating that such a complex and horrific act could only stem from extreme hatred, reminiscent of ancient acts of desecration.
The next morning, Qiao Chusheng woke a still-sleeping Lu Yao with a splash of water, eager to share new leads. His team discovered that Liu Yansheng and Guan Dailiang had secretly collaborated on research into epidemic cerebrospinal meningitis, a project later banned by the medical school. Guan Dailiang, to protect himself, exposed Liu Yansheng, leading to Liu losing all his research and igniting a deep feud between them. Qiao Chusheng considered this a strong motive for murder.
Qiao Chusheng had also learned that Guan Maoliang and Guan Dailiang had a significant dispute over their late father’s inheritance. Guan Maoliang, a compulsive gambler deeply in debt, was being aggressively pursued by creditors. Qiao Chusheng arrested him. During the interrogation, Lu Yao confronted Guan Maoliang about returning to the lab for a box of rose cake, which Lu Yao suspected contained arsenic.
He revealed that the red specks in the cake, unlike ordinary rose sugar, reflected light under strong illumination, identifying them as impure arsenic. Lu Yao then had Guan Maoliang place his hand on the table, pointing out traces of low-concentration potassium permanganate, which he had covertly applied to the cake, knowing these traces could not be easily washed off and would expose Guan Maoliang’s guilt.
However, Qiao Chusheng’s investigation revealed that Guan Maoliang had recently paid off all his debts, strongly suggesting he benefited from his brother’s death. Despite the mounting evidence, Lu Yao deduced that Guan Maoliang was not the killer. He explained that the rose cake found in the lab was still fresh and glossy, indicating Guan Dailiang had never opened it.
Furthermore, someone proficient in chemistry, like the actual killer, would know how to remove potassium permanganate traces, which Guan Maoliang evidently did not. Guan Maoliang then confessed that his creditors had pushed him to consider the inheritance. He bought the arsenic-laced rose cake but couldn't bring himself to poison his brother. Knowing Guan Dailiang never ate in the lab, he left the cake there. Upon hearing of his brother's death, he panicked, fearing suspicion, and returned to retrieve the cake.
A breakthrough came from the coroner, who, following Lu Yao’s persistent urging to meticulously examine the victim's head, discovered a tiny pinhole at the nape of Guan Dailiang’s neck, directly in the medulla. This indicated that a sharp medical probe had been used to stab the life center, causing instantaneous death. The precision of the single pinhole suggested a highly skilled individual with knowledge of medicine or anatomy.
This new evidence effectively ruled out Guan Maoliang, leaving Lin Ai and Liu Yansheng as the primary suspects. Lu Yao proceeded to check the chemical supply registers for potassium permanganate and formalin. During his visit, he encountered Liu Mo, who, recalling Lu Yao’s mischievous antics at Cambridge, including stealing reagents and notes, and forcing him to skip classes, leading to Liu Mo repeating a year, angrily tried to attack Lu Yao.
Lu Yao skillfully evaded him and, later with Qiao Chusheng, visited the medical school’s poultry house, reasoning that animal experiments required such facilities. There, they found Liu Yansheng was the person in charge. Lu Yao deduced that Liu Yansheng, as the manager of a facility requiring regular disinfection with formalin and potassium permanganate fumigation, would have extensive access to these chemicals. However, upon entering, they discovered Liu Yansheng’s body in the bathroom.
He had been murdered in the exact same manner as Guan Dailiang: with brown chemical residue and a pinhole at the back of his neck, confirming a serial killer was at large. Bai Youning quickly published an exclusive on the "Formalin Serial Murder Case" in the New Moon Daily, a headline that quickly spread across Shanghai. Her father, Bai Qili, summoned Qiao Chusheng, urging him to solve the case promptly.
Bai Qili revealed his true motive: he sought to join the St. George University school board to challenge the foreign monopoly on Western medicine production and patents, seeing it as crucial for China’s future amidst impending large-scale wars. He explicitly identified "those Englishmen at the Manson Club" as the masterminds behind this "battle without gunpowder." Lu Yao, however, chastised Bai Youning for publicizing the case.
He argued that modern medicine depended on dissections and specimens, and her article, which highlighted the victims' previous efforts to persuade body donations while also emphasizing the belief that "dissecting a body will be punished by Heaven," would deter future body donations and hinder medical progress. Bai Youning defended her article as merely describing objective facts gleaned from her investigation into the victims' past activities.
Bai Youning later interviewed Liu Mo, who, upon learning that she shared an apartment with Lu Yao, launched into a scathing critique of Lu Yao’s character. He described Lu Yao as selfish, capricious, disloyal to friends, and inhumane to girlfriends, citing an instance where Lu Yao abruptly abandoned an intelligent and beautiful economics major girlfriend to go to Paris.
Liu Mo warned Bai Youning about Lu Yao's "intimacy issues," claiming that he would panic and flee whenever someone got too close, causing the most hurt when emotions ran deepest. Meanwhile, Lu Yao visited Lin Ai at her rented apartment. She was visibly nervous and resistant, suspecting he believed her to be the murderer.
Lu Yao revealed that he knew she had spent eight hours in Lab 301 on the day of Guan Dailiang's murder, from 1 AM to 9 AM. Lin Ai explained she was culturing soybean rhizobium, a process requiring constant temperature monitoring and repeated cooling with water, which necessitated her continuous presence. Despite her detailed explanation, Lu Yao expressed skepticism, finding it hard to believe anyone could remain stationary in a hot lab for such a long period.
Lu Yao later discussed Lin Ai with Qiao Chusheng, pointing out the discrepancy between her current luxurious lifestyle and her family's humble background two years prior. Qiao Chusheng, observing Lu Yao's concern, playfully suggested he had a romantic interest in Lin Ai.
Nevertheless, Lu Yao concluded that based on her detailed alibi, which involved an experiment taking seven hours and forty minutes and her confirmed appearance at 8:42 AM to display results, she must have started at 1:02 AM, making it impossible for her to have committed the murder and submerged the body in formalin within a mere two minutes of entering the lab at 1 AM. Despite this, Lu Yao still intended to return to the lab to personally verify her claims.