First, He Yong's suspicion of He Yun. There are many things that make He Yong doubt He Yun. The first is the trial of Ma Shuai. Although the story behind said that He Yun offered to cooperate with He Yong, it can be seen that He Yong should know something about He Yun's appearance, but in a few words, it is doubtful that He Yun died at the hands of Ma Shuai. Of course, He Yong didn't doubt it at first, until Ma Shuai's death was tampered with, the forensic doctor was He Yun's classmate, and He Yun took the initiative to report it when Chen Jianbo tried.
Second, Luo's doubts. Wang Zheng should be the big umbrella of evil forces. Up to now, Wang Zheng didn't leave the factory for much time, but in the first episode, when he took over the supervision team, only Wang Zheng turned his back on everyone, which should be a foreshadowing laid by the director. In the latest story, Zhao and Suodong showed Luo the material of Li Chengyang's dismissal, and finally signed it, which should also imply that it will also surface.
Third, other small shrimps. Except He Yun and Wang Zheng, I think all the others are shrimp, because both Dong Yao and Mayor Wu are members of the administrative unit, and they were also found by Li Chengyang one by one. Besides, some people suspect that it is Peivie. Although Peivie's performance during the trial of Chen Jianbo was questionable, only He Yong and Peivie knew about sending Ma Shuai's samples to secret testing, which was problematic. Therefore, I still doubt whether Peivie is the mole.