In this gripping thriller, Ma Shan (Wen Jiang), a Chinese police detective, wakes up one morning after a heavy night of drinking at his sister’s wedding reception to discover that his gun has been stolen. This theft raises concerns for Ma Shan as only police officers are authorized to carry firearms. Fearing the dangerous implications of his weapon being in the wrong hands, he embarks on a mission to locate it. However, both Ma Shan and his friends struggle to recall the events of the wedding, making it difficult to determine who drove him home. The situation intensifies when his ex-girlfriend visits town and is tragically found dead, with ballistics confirming that the bullets were fired from Ma Shan’s missing gun.