Episode 4 recap: Wang Xin got punished for getting off the vehicle without authorization.

Wang Su Fang believes that the current Wang Xin is just like Ma Kui back then, both of them have angered their mentors to the point where they have no words to say. After mocking Ma Kui, Wang Xin arrived at that moment, and Ma Kui sat down to sarcastically tell Wang Xin to go back and wait for commendation. Wang Xin didn't grasp the meaning behind Ma Kui's words, so Ma Kui had no choice but to seriously criticize Wang Xin, blaming him for not following his orders and directly jumping out of the window and off the vehicle. Wang Xin felt that he was in a hurry to catch the thief, and there was nothing wrong with jumping off the vehicle. He also expressed that it was the attitude a police officer should have when catching a thief.

Ma Kui saw that Wang Xin didn't understand his concern at all, had no awareness of the danger, and harshly scolded him, even resorting to physical confrontation with Wang Xin. Wang Su Fang and Ma Yan heard the commotion and immediately came out to intervene. They blamed Ma Kui for starting a fight with Wang Xin and couldn't understand Ma Kui's actions.

Wang Xin went back and told Wang Yong Ge the truth of the matter, and Wang Yong Ge also sided with Ma Kui, believing that Wang Xin had made a mistake by not obeying orders and going after the thief on his own. In the evening, Wang Su Fang made a cup of milk, hoping to please Ma Yan, but Ma Yan still treated Ma Kui poorly because he had hit Wang Xin. Ma Kui didn't achieve a good outcome, and it was only when Wang Su Fang comforted him that he expressed his appreciation for Wang Xin, stating that he was trying to toughen Wang Xin up and was worried that Wang Xin was too reckless and didn't know how to protect his own safety. Niu Da Li waited for Yao Yu Ling to leave for work together, but Yao Yu Ling didn't want to go with him at all, so she made an excuse to go back and sent Niu Da Li away.

Yao Yu Ling waited for Wang Xin to come out and go to work together, while Ma Yan specifically came to explain to Wang Xin about Ma Kui's actions of hitting him, so she blocked Wang Xin's way. Ma Yan didn't know what to say when she saw Yao Yu Ling by Wang Xin's side, so she let Yao Yu Ling go first and then explained on behalf of Ma Kui, asking Wang Xin not to take it too seriously.

Wang Xin was filled with anger and couldn't accept Ma Yan's explanation, so they parted ways. Back at the police station, Hu Dui Zhang held a meeting to discuss Wang Xin's unauthorized act of getting off the vehicle to chase the thief, and Wang Xin realized his mistake of not following orders and accepted the punishment from his superiors. After Wang Xin's self-reflection, Ma Kui expressed that his thinking had been slow and he didn't timely realize the thief's tricks, causing the passengers to suffer losses and leading to Wang Xin's mistake of getting off the vehicle to chase the thief, so the blame was entirely on him.

Wang Xin heard what Ma Kui said and realized that Ma Kui genuinely cared for him. He changed his opinion of Ma Kui and started calling him "Uncle" in a friendly manner.

Niu Da Li felt uncomfortable and finally gathered the courage to talk to Lao Wu about the Egg King incident. However, he was surprised to find out that Lao Wu had already known that Niu Da Li was the one who stole the Egg King. Niu Da Li explained that he didn't know he had caught the Egg King and that the chicken he bought was sick. Nevertheless, he admitted that he felt guilty about the whole situation.

Lao Wu forgave Niu Da Li, which made Niu Da Li happy to continue working. However, other colleagues couldn't help but mock him. Tang Xing Guo happily returned to Ningyang with his partner, Li Yuxiu, but he discovered that his Shanghai brand watch, which he bought, was stolen from his bag on the train.

Tang Xing Guo panicked when he realized his watch was missing and immediately called for Ma Kui and Wang Xin to help. At that moment, Ma Kui noticed a suspicious person and decided to chase after them, leaving Wang Xin to handle the record-keeping. The thief who stole the watch hid in the restroom and threw the watch into the cesspool. Ma Kui arrived a bit late, caught the thief, but couldn't retrieve the watch.

Li Yuxiu didn't see the watch, and she got upset because it was missing. She started arguing with Tang Xing Guo and even suspected that he never bought the watch and made up the story of it being stolen. As a result, she refused to marry Tang Xing Guo.

Upon hearing that Li Yuxiu didn't want to marry him, Tang Xing Guo became desperate and started crying. After Li Yuxiu reassured him repeatedly, he decided to harm himself by cutting his wrist. Wang Xin noticed in time and took Tang Xing Guo for treatment, saving him from harm. Ma Kui assured Tang Xing Guo that even though they hadn't recovered the watch, they had identified the thief. He urged Tang Xing Guo and Li Yuxiu to stop arguing and continue their happy days together, which eventually resolved their differences.

In the process of apprehending the thief of the watch, Ma Kui injured the thief's hand but couldn't find the stolen item. As a result, the thief accused Ma Kui and demanded compensation. After being scolded by Hu Dui Zhang, Ma Kui interrogated Hou San Jin alone and used his own methods to scare him. Frightened, Hou San Jin immediately tore up the forged hospital documents and no longer dared to ask Ma Kui for money, only pleading for Ma Kui to spare him.

When Hou San Jin admitted that he was extorting money from Ma Kui, Ma Kui demanded that he tell the truth and confess what happened on the train.