An operation to take down a group of men trading illegal firearms has ended in just seven minutes. Several gunmen were killed and their leadeer Xu Zhihai was captured. The mission was completed swiftly but police bureau chief Li Jian remains anxious because of the major gun-related cases occurring along the borders.
Under Li Jian's orders, investigator Zhang Meng enters prison undercover to dig up clues from Xu Zhi Hai. Zhang Meng eventually wins the trust of Xu Zhi Hai but fails to gain any information about the gun smuggling. By chance, Xu Zhi Hai manages to escape prison while Zhang Meng doesn't hesitate to follow him. Xu Zhi Hai is shot by police officers while on the run and before his death, he instructs Zhang Meng to go to Russia to find his older brother Xu Zhi Qiang.