Starring Jiang Wen and Jingning, it tells the story that Mashan, a policeman, woke up after a night's dream and found his gun missing. There are three bullets in the lost gun. Because of the gun throwing incident, the title of "advanced collective" of the police station was not guaranteed, and Mashan could not be rated as "advanced individual". Later, Mashan's ex-lover Annabel Lee was shot, and the town seemed to be shrouded in dense fog and full of danger. As a result, Mashan began to embark on an unusual road of looking for guns.

The story of "Looking for a Gun" has twists and turns, which combines many performance elements such as suspense films, thrillers and psychological horror films, and interprets the living dilemma and psychological world of ordinary people from a new perspective.