In the 1930s, China was in a state of turmoil and flurry. The dethroned Emperor Pu Yi had established the Puppet State of Manchukuo in Manchuria and was cooperating with the Japanese in the testing of poisonous gas. The revolutionary army headed by Lieutenant Mong is assigned to crush this vicious plot. During his mission, Mong 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. How can Uncle Choy prove himself? And can they succeed in their mission?