Set against the backdrop of the Chinese Civil War, the film tells the story of a secret agent named Lin Xi. Lin Xi, a covert operative working for the Communist side, is tasked with rescuing a fellow spy codenamed "Green Snake" who has been captured by the enemy. His mission is to help "Green Snake" deliver crucial defense plans of Jinzhou city to the People's Liberation Army outside the city, thereby supporting the assault on Jinzhou.

Border drug lords thrive as anti-narcotics police fight fiercely. Vice Captain Xiao Ruolan falls into a trap during a raid, missing, while an impostor infiltrates the force. Drug lord Chen Qiang plots a major deal. Conflicts erupt: real vs. fake Xiao, cartel infighting, and gunfights. Who survives when the truth emerges?