Qi Sizhe speculated that the specimen room was probably the first scene. According to this idea, the opened iron mesh Zhu Qingyue found in the back mountain was most likely the place where the murderer fled the scene.Wan Guoxin led people to search for heads in the back mountains.Qi Sizhe and the others went to the specimen room.A lot of blood stains were detected on the floor of the specimen room, extending to the specimen shelf. Han Feng and the others moved the shelf and discovered that there was a secret room behind the specimen shelf.

In the room, in addition to the brain specimen, there was also a notebook. Zhu Qingyue flipped through it and found that the preparation of the head specimen was recorded in it. Huang Zhengming's name was written on the lower right corner of the title page.Qi Sizhe checked the mop and bucket. There was a reaction after the luminol reagent was sprayed. Qi Sizhe told Han Feng that this was probably the first scene of dismemberment.The school leader told Han Feng and the others that the two rooms used to be connected, but later they became empty, and the room on the left was turned into a specimen room. He didn't know anyone else was using that laboratory. Maybe Professor Huang Zhengming was assigned a key when he moved to the new building, so he was using it secretly. Professor Huang Zhengming, an old expert in brain nerves and anatomy, was known as Huang Yidao.

Han Feng and Zhu Qingyue went to check Huang Zhengming's office. Han Feng found a takeaway. The name of the restaurant on it was Spring Restaurant, which was where Liu Yuanyuan worked.After testing, Qi Sizhe found that what was found in the room was not Liu Yuanyuan's head.Huang Zhengming was taken back to the police station. He admitted to using school resources to conduct experiments, but firmly denied murder and dismemberment. He said that the laboratory next to the specimen room was not his, and he only used it for his experiments.

Han Feng took out the takeout order, and Huang Zhengming said that he didn't want it to be troublesome, so he chose a restaurant to deliver the food. Since he always asked the clerk to leave it outside the door, he still has no idea who delivered it.Qi Sizhe sent a message to Zhu Qingyue and explained in detail that the research Huang Zhengming was doing required a large amount of experimental data. Huang Zhengming said without hesitation that as long as his experiment could succeed, he was willing to kill people, but asked the police to provide evidence.

After Han Feng and the others left the interrogation room, Huang Zhengming looked at the lamp above his head, his hands still shaking. Qi Sizhe looked at Huang Zhengming's watch and remembered that he had seen Li Ming wear it before. He told Han Feng the situation, but Han Feng still didn't believe it.

The police found six heads in the woods behind the mountain. Huang Zhengming gave an explanation. Some were obtained through the donation center through personal relationships, and some were removed from unwanted human specimens at the Medical University.Li Xiaoxi made a new discovery. Gao Yuan confirmed that the hammer wound on Liu Yuanyuan's head was a fatal injury. Qi Sizhe concluded that the time of death was between 2 and 6 pm five days ago. He said that judging from the skull, Huang Zhengming did not use Liu Yuanyuan's head for brain research.The handwriting of the donor list provided by Huang Zhengming is very close to the handwriting in the second half of the notebook, but completely different from the handwriting in the first half of the notebook. Qi Sizhe said that both handwritings are Huang Zhengming's because he has Parkinson's disease, and Liu Yuanyuan's head incision is very smooth, which is not what Huang Zhengming can do.Wan Guoxin checked Huang Zhengming's social connections and ruled out the possibility of someone helping him kill.

Qi Sizhe stopped Huang Zhengming and asked him if the watch belonged to Li Ming. Huang Zhengming was very irritable and refused to answer his questions at all.According to interviews and investigations, the three suspected professors all have alibis.After reorganizing the case, everyone found that after Liu Yuanyuan brought so many things to the Medical University, they disappeared. Moreover, Liu Yuanyuan's friends once said that she could have attended the Medical University.

Li Xiaoxi told Han Feng that Gao Huilan and the students pushed a corpse bed and left the specimen building. The students were very afraid of corpses. He and Li Xiaoxi went to investigate what happened.On the other hand, Zhu Qingyue and Wan Guoxin went to visit Liu Yuanyuan’s school and the invigilator.The invigilator was very impressed and said that Liu Yuanyuan looked very much like one of her students, Ding Youmei.After checking, it was discovered that Ding Youmei worked as an assistant professor at the Medical University and was Gao Huilan's daughter.

Back then, Yu Fei became a forensic doctor with the help of Qi Sizhe. He had always felt guilty. He swore in front of Yu Fei's grave that he would find out the truth and give her an explanation.