Episode 37 recap: Wang Xin and Ma Kui arrested Liu Gui Ying.

Niu Da Li wanted to get a soft sleeper berth, but there was an elderly cadre in the berth who strongly protested, saying that Niu Da Li was not qualified. Niu Da Li insisted on taking the soft sleeper, while the elderly cadre was concerned for his own safety. Lao Xia Zi recalled that his two-year-old daughter was kidnapped in 1963 on a train from Ningyang to Hacheng. Lao Xia Zi had been searching for her for 32 years on that train, his eyes eventually going blind from crying, but he could never forget the kidnapper's scent and the large dark mark on the woman's face.

When Lao Xia Zi described the physical characteristics, Wang Xin realized the kidnapper he saw, Liu Gui Ying, was the same person. Wang Xin gently advised Lao Xia Zi, swearing to catch the kidnapper, and believing that his daughter was living well now. Ma Kui also persuaded Lao Xia Zi to live well.

Ma Yan wanted to quit her job and go into business, but Ma Kui firmly refused. Ma Yan threatened a hunger strike, and Wang Xin and Ma Jian pleaded for her, but Ma Kui did not believe them, thinking Ma Yan was just acting. Ma Kui and Wang Yong Ge were neighbors. When Wang Xin accompanied Wang Yong Ge on a walk, Ma Kui went to check on Ma Yan, who was pretending to be sick in bed. When Ma Kui "left", Ma Yan quickly got up to eat, but was caught by Ma Kui, who still refused to let her go into business. Ma Yan vented to Wang Xin, who came up with a good solution.

Wang Xin called both families together for a vote. Ma Yan was confident, having bought Ma Jian a new pair of shoes to get his support vote. Wang Xin supported Ma Yan quitting, but Ma Jian suddenly switched sides to support Ma Kui, having been influenced by him. Ma Yan realized Ma Kui had also gotten to Wang Yong Ge, who ended up abstaining, simply saying "the Beijing-Kowloon railway will soon be operational" before going inside.

The vote ended in a 2-2 tie, angering Ma Kui, who left with Ma Jian. That night, Wang Xin accompanied Ma Yan to negotiate with Ma Kui, who eventually relented after Wang Xin assured him Ma Yan would not suffer. Ma Yan and Wang Xin were overjoyed.

On the soft sleeper train back to Ningyang, Niu Da Li and his assistant enjoyed the amenities, much to the annoyance of the elderly cadre, who strongly protested Niu Da Li's lack of qualification. The conductor tried to explain the new railway regulations, but the cadre remained unconvinced.

Yao Yu Ling was in the next-door soft sleeper, and she recognized Niu Da Li's voice, so she came to take a look. Yao Yu Ling and Niu Da Li hadn't seen each other in years. They went out to the corridor to catch up. Yao Yu Ling learned that Niu Da Li was still unmarried, and she advised him to settle down soon. Niu Da Li learned that Yao Yu Ling had left him back then to marry Jia Jin Long, and he felt quite uncomfortable about it. Yao Yu Ling hesitated, but in the end, she only said, "She always remembers Niu Da Li's kindness," and then went back to her own compartment. Niu Da Li was in a mixed state of emotions.

Wang Xin and Ma Kui were also on this train. They happened to run into the couple who had argued on the train due to a misunderstanding years ago. They had not only gotten married but also had a seven or eight-year-old son, whom they had named "Lü Pi." They wanted to invite Wang Xin and Ma Kui to dinner, and Wang Xin and Ma Kui were happy for them. Ma Kui quietly reminded Wang Xin to have a child soon.

Suddenly, Ma Kui's bag under the seat disappeared. It turned out that Ruo Ruo had brought it to him. Ruo Ruo reminded him to keep an eye on his bag. Ruo Ruo poured out his heart, saying that after being released from prison, he had learned the craft of tailoring and was now able to support himself. Wang Xin and Ma Kui were overjoyed to see that Ruo Ruo had become more confident and strong.

A little boy walked past Lao Xia Zi, and seeing Lao Xia Zi in a pitiful state, he gave him a steamed bun. Lao Xia Zi suddenly caught the familiar scent of a human trafficker, and he reported this to Xiao Hu. Xiao Hu notified Wang Xin, who went over to the little boy and gave him a bucket of drink. The boy's mother was covered up tightly, and Wang Xin gave her a bucket of drink as well, but she refused to reveal her true identity. Wang Xin reported this to Ma Kui, and Lao Xia Zi was convinced that the woman was a human trafficker.

The woman took the little boy and got off the train. Ma Kui and Wang Xin followed them closely. They went to a noodle shop, and Ma Kui asked Wang Xin to keep an eye on the shop while he went to the opposite steamed bun shop to gather information. Soon, Ma Kui contacted the local police. The police found out that the noodle shop owner's name was Zhu Yue Zhen, and she lived in an unexpected place called San Dao Gou, over a hundred miles away. Wang Xin was worried that too much time might pass, so he wanted to head to San Dao Gou right away.

Ma Kui and Wang Xin rushed to San Dao Gou that night. They found out that Zhu Yue Zhen's real name was Liu Gui Ying, and she had spent a few years in prison before. She had the skill of steaming buns. Three years ago, Liu Gui Ying's husband had passed away, and she had left with her son and daughter. Wang Xin confirmed that Liu Gui Ying was the human trafficker, and they had the local police arrest her.