Ah Wei used to be a policeman but his many battle scars and bullet wounds have demoted him to the daily grind of a sercurity guard. His existence is anything but boring, however, as this Hong Kong film like all the others, thrives on shoot-outs, chases, and enough violence to keep an audience awake.

In Hong Kong, Circa 1940s, World War II, private detective Yoyo and friend Inspector Teddy Robin join a resistance group during the Japanese occupation. They aim to steal back the formula to the atomic bomb from a war traitor and transfer it to an American before the formula ends up in the Japanese emperor's hands.