While Shen Yu was looking at the Haizhou case information in the office, Xia Mu suddenly came in from the door, broke her behavior on the spot, and accused her of avoiding the date of Shen Haiyang’s disappearance. He went to the police only two weeks later. Xia Mu repeatedly insisted on identifying Shen Haiyang as the murderer of the Haizhou case. Shen Yu took the initiative to mention Xia Yuanchao and mocked Xia Mu for not having the courage to go back to hold the funeral for his grandfather, so that the body is still lying in the funeral home.
Shen Yu threatened Xia Mu with Xia Yuanchao's photos, which caused him to faint due to illness. Leng Xiaobing learned that Xia Mu had been sent to the hospital for emergency treatment, and rushed over. Suddenly he remembered the abnormal behavior Xia Mu had done before, so he went to the interrogation room again and deliberately emphasized Wu Chaochao, hoping that Cao Yingxia would tell the truth for his son.
Cao Yingxia gradually calmed down and explained the ins and outs, because her husband did not allow her to see her son, so she killed him impulsively. From beginning to end, Cao Yingxia was pretending to be crazy and stupid. She did not expose her husband to the outside world as a well-dressed beast, and did not want her son to be discriminated against and criticized for the rest of her life.
After the interrogation, Leng Xiaobing went to the hospital to visit Xia Mu, curious about the content of the conversation between him and Shen Yu, half-jokingly questioned whether he had a handle in the other's hand, and took out the prescription drug list. Xia Mu explained that he had recently suffered from insomnia. Leng Xiaobing knew that he was lying and did not continue to question. When they left, they met Shen Yu head-on, and the two hinted at a rivalry.
Hu Daodao confessed to Shen Yu, but Xia Mu had to confess the surveillance. Considering that Shen Haiyang was most likely a murderer, Hu Daodao suggested that Shen Yu should not be too obsessed, even if he found his father, he would not be able to live normally as before. Shen Yu was noncommittal, but asked Hu Dadao to remove the monitoring and delete all the information.
In just a few days, Xia Mu fainted and was hospitalized for the second time. Gao Peng thought he was in poor mental state recently and decided to give him a few days off. After Leng Xiaobing learned about it, he told Chen Han to follow Xia Mu and never let him do stupid things. Xia Mu came to the hospital at this time, threatening to never let Shen Yu go, and even questioned her as a psychologist, why she was so cold-blooded.
Shen Yu retorted angrily, saying that Xia Mu was able to find Shen Haiyang to prove his murder, and he was willing to bring his father to justice, but that was not the case. Then Shen Yu handed Xia Yuanchao's things to Xia Mu, persuading him to walk out of the past. That night, Xia Mu returned home alone, feeling extremely depressed and resentful, smashing things crazily to vent, under the influence of alcohol, vaguely saw the late grandfather.
On the other side, Leng Xiaobing locked the phone number of Shen Haiyang’s home that year based on the phone number derived from the old walkie-talkie. Chen Han reported to Leng Xiaobing how Xia Mu left the police force during the day and what happened. It was strange that Xia Mu went to find Shen Yu with nothing but a box when she came out, suspecting that Shen Yu had given it to Xia Mu.
Leng Xiaobing learned about Xia Mu's situation, and went to the place where Xia Mu was alone late at night. Seeing him frustrated in the underground passage, he couldn't help but comforted him, and the two talked freely. During the conversation, Leng Xiaobing handed the phone number circled in red pen to Xia Mu. His ideas coincided with him, and they all believed that this was a clue that could be broken through.
Since Xia Jinlan was killed, Xia Mu has not spoken, and later went to the wetland protection station with her grandfather. Because the place was isolated from the world, she slowly forgot the past. However, after Xia Yuanchao was killed, Xia Mu felt that everything was back to before. Leng Xiaobing persuaded Xia Mu to go back to see his grandfather, but Xia Mu really had no face to go back and decided to wait until the matter was over before giving grandpa a good funeral.
The next morning, Leng Xiaobing pushed the door in and found that Xia Mu had stayed up all night and checked the clues, but still made no progress. At this time, Leng Xiaobing received a call and learned that a new murder had occurred in Rongcheng's home. When Leng Xiaobing arrived at the crime scene, it was determined that the deceased was a woman. She was immersed in the bathtub with pinholes in her neck and arms. She wore a weird smile on her face. An alarm clock was found at the crime scene with the Haizhou case. The same modus operandi.