Chasing the Murderer with a Black Gun

A fire broke out in a rented house in Shanghai. Yu Shengnan (played by Qi Fang), a female professor at the Medical University, found a female corpse that was very suspicious, so she quickly called in the patrol room inspector Zhong Lang (played by Zhong Hanliang) and his partner Han Fei (played by Shi Xiaolong) decoration). After preliminary autopsy and on-site investigation, Sheng Nan and Zhong Lang concluded that the deceased was murdered before the fire. After further investigation, the deceased's daughter was declared missing when the fire broke out, and various signs indicated that there was a child kidnapping case behind the murder. Zhong Lang and others found the deceased's sister, and the other party pointed all accusations and suspicions at Xu Shengdao, the brother-in-law who had never shown up. Zhong Lang and the other three came to Xu's residence and were attacked by several thugs, who turned out to be the special commissioner of the Nanjing Military Commission. It turned out that Xu Shengdao was a rifle designer at a military factory. The rifle he designed had a serious quality problem that caused the barrel to explode, causing unnecessary casualties to the soldiers on the front line. The Nationalist Government sent people to investigate the matter, and Xu himself was declared missing a few months ago. The confusing case within the case, the intricate clues, everything points to the layers of shady behind the scenes...