Episode 31 recap: Wang Xin and Ma Kui are investigating the case of a missing female college student.

Late at night, Yao Yu Ling went to find Wang Yong Ge to discuss her resignation and asked Wang Yong Ge to help persuade her employer to let her keep her belongings at her place for a while longer until she can come to collect them. Wang Yong Ge was surprised by Yao Yu Ling's decision, but she refused to explain the reasons behind it. He could only wish her well and hope that she would be happy with Niu Da Li and not be deceived by others.

Wang Xin brought up the topic of marriage again, asking about Ma Kui and Wang Yong Ge's relationship. He believed that Wang Yong Ge might have done something to offend Ma Kui, which is why Ma Kui strongly opposed Wang Xin's relationship with Ma Yan. Wang Yong Ge insisted on not revealing what happened in the past, only stating that his problem lies with Ma Kui and he won't allow Wang Xin and Ma Yan to be together.

Peng Yong Li has graduated and is planning to get married soon. After the wedding, she will continue to live in Ningyang, so Ma Kui allowed her to stay at his place. At Ma Kui's request, Peng Yong Li agreed to live with him and asked him to be her witness at the wedding. Ma Kui accepted Peng Yong Li's request and celebrated with her and Peng Ming Jie at home.

Another female corpse, Chen Li Mei, was found by the river. Her cause of death resembled the dismemberment case involving a train, indicating that it might be the same perpetrator. Wang Xin found a set of footprints at the crime scene and estimated the height and weight of the killer, but there were no other clues left by the perpetrator. Liu Ming visited Shen Xiu Ping for medical treatment and expressed his gratitude to her for helping him recover from his illness. He gave Shen Xiu Ping two cans of canned food as a gift.

Shen Xiu Ping declined Liu Ming's gift but failed to perceive Liu Ming's intentions. She inadvertently caused trouble for herself by not cutting off Liu Ming's infatuation. Peng Yong Li moved her luggage to Ma Kui's house and asked if he was ready with the marriage vows since the wedding day was approaching. Ma Kui reminded Ma Yan to make time to prepare the new house and arrange everything needed for the wedding.

There was a case of a missing female college student on the street. Captain Jiang assigned Ma Kui and Wang Xin to investigate. Wang Xin questioned many people on the street where the student disappeared and finally confirmed that the missing student was abducted by the human trafficker Liu Gui Ying.

After Yao Yu Ling resigned, she went to Ha City with Jia Jin Long, and the two of them were very sweet together. Jia Jin Long gave a denim jacket to Wang Xin as a gift and hurried to catch a train back to Ha City. Wang Xin thanked Jia Jin Long for his kindness and asked him to help gather information about drug dealers in Ha City.

Jia Jin Long learned that Wang Xin is in charge of drug trafficking cases in Shenzhen and understood the dangers involved. He reminded Wang Xin to be extra careful and offered to keep an eye out for any leads.

Shen Xiu Ping returned home after work, but Liu Ming deliberately ran into her again, hoping to cling to her and ask her out for a meal to reconcile. This time, Shen Xiu Ping sensed Liu Ming's intentions and didn't want to accompany him or let him walk her home. However, Liu Ming persisted, so she had to lie and say that she left something at the hospital and asked Liu Ming to leave first.

Ma Kui encountered Lao Xia Zi on the train and had a brief conversation with him, also taking the opportunity to assess his own sense of smell. Wang Xin invited Ma Yan to have a meal and took her to the restaurant they often visited for noodles. Unexpectedly, the owner added a lot of meat to their noodles.

During Wang Xin's previous visit to the restaurant, the owner gave them a lot of meat, claiming it was because he was in a good mood. This time, it happened again, raising Wang Xin's suspicion. Just as Wang Xin was suspicious, other customers arrived at the restaurant, and he noticed that their bowls didn't have as much meat, further confirming his doubts.

When Wang Xin finished eating and went to pay, the owner's wife claimed that they didn't need to pay for the noodles. This made Wang Xin even more certain that something was amiss with the restaurant. After leaving the restaurant, Wang Xin returned to investigate and discovered that the owner of the noodle shop was Chen Xiao Fei.

Chen Xiao Fei had turned over a new leaf and opened a noodle shop to make a living. He got married and had a son, making his mother live a better life. He was particularly grateful to Wang Xin for helping him change his ways. Wang Xin felt a strong sense of honor as a police officer because of Chen Xiao Fei's transformation.

As Ma Yan began to resemble Ma Kui more and more, she once again pressured Wang Xin to resolve the issues between her and Ma Kui. Wang Xin couldn't change Ma Kui's mindset, so he could only joke with Ma Yan and carry her away.

When Shen Xiu Ping finished work in the evening, Liu Ming once again harassed her, revealing his background and expressing his desire to be with her as a couple. Shen Xiu Ping repeatedly stated that she didn't want to know Liu Ming and didn't want to become familiar with him, but Liu Ming clearly wasn't giving up.

Ma Kui returned from a business trip and wanted to pick up Ma Yan from Shen Xiu Ping's home, but Ma Yan was already asleep. He stayed for a while and then left. Ma Kui accidentally left his scarf behind, and Shen Xiu Ping specially brought it to the doorstep to give it to him, but she was unexpectedly seen by Lao Cai's wife, who misunderstood the situation.

Lao Cai's wife believed that Ma Kui and Shen Xiu Ping were living together and hurriedly went to gossip with Lao Wu's wife. Unexpectedly, the gossip spread to all the women in the neighborhood, causing it to quickly circulate throughout the community.