The time is 1930s.
China is in a state of turmoil and flurry.
The dethroned Emperor Pu Yi establishes the puppet state of Manchukuo in Manehuria and is in cooperation with the Japanese in tests for poisonous gas. The revolutionary army headed by Lieutenant Mong is designated to crush this vicious plot. During this mission, he comes across witty and valiant veteran Uncle Choy and his friends, who volunteer to help. Mong believes that Uncle Choy is too old to join them. Directed by Tsui Har and Ching Siu Tung.