Desperate sniper chase in the line of fire

In the old Shanghai before liberation, all forces gathered here, one was declining and the other was growing, and they were domineering. The two major underworld forces, the Qinglong Gang and the Qilin Gang, often fight for supremacy, with blood splattering on the streets. One day, three members of the Qinglong Gang were found dead on the street. Yu Shengnan (played by Qi Fang), a female professor at the Medical University, Zhong Lang (played by Zhong Hanliang), the "Tiger Inspector" of the patrol room, and Han Fei (played by Shi Xiaolong), an intern, rushed to the scene to investigate. It was found that the deceased were all shot by masters with extremely accurate marksmanship using "dum bullets". Zhong Lang concluded that the murderer was a sniper with a military background. At the same time, Liu Tianhe, who claimed to be a veteran of the Northern Expeditionary Army's Independence Regiment, appeared in front of them and revealed the true identity of the murderer to everyone. On the other hand, the boss of the Qinglong Gang believes that his men were murdered by the Qilin Gang. The two sides are at war with each other, and an unprecedented bloody storm is about to start in Shanghai. In order to avoid a larger-scale armed fight, Zhong Lang must race against time to find the real murderer...