Searching for a Gun

Ma Shan (Jiang Wen) is an ordinary policeman in a border town in the southwest region. When he attended his sister's wedding banquet one night, he was drunk and was sent home. When he woke up the next morning, he found that the gun he never left behind was missing. When he realized that the gun thief could kill with three bullets in the gun, Ma Shan couldn't help but feel horrified. Everyone who attended his sister's wedding that night became the object of his suspicion. After tracking down the key suspects, Liu Stutter, who sells "mutton noodles", Zhou Xiaogang who sent him home, and his old lover Li Xiaomeng (Ning Jing) who suddenly appeared at Zhou Xiaogang's house, Ma Shan still couldn't figure out any clues. His suspicion of Li Xiaomeng was mixed with extremely complicated feelings, which led his wife to suspect that he was in another relationship. At this moment, Li Xiaomeng was shot to death at Zhou Xiaogang's house, and Ma Shan was detained as a suspect. After some calm thinking, he finally sorted out the mess and started looking for the gun.