Nameless Heroes.

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.