Hidden and Great is a China TV series. All the information I have learned is based on the premise and plot of the drama, but I may not be able to provide specific details of the plot. As far as I know, beating the bell at the gate of the police station may be related to the following situations:

Xia Jicheng is one of the main characters in the play. He was a retired special soldier and later became a private investigator. The play describes his complicated relationship with Zhong.

Zhong may be an opponent or an enemy in the play, and there may be some contradictions or conflicts between them. Specifically, Xia Jicheng may have a deep resentment or anger towards Zhong, which led him to beat Zhong in front of the police station.

Please note that because I can't provide the specific plot and details of the series, the above is just a guess based on roughly similar plots. If you have more specific questions about the story, I suggest you check the story itself or related story introductions and comments to get more accurate information.