A private investigator and a police inspector team up to pursue a notorious mobster, who is plotting to milk an old millionaire out of his highly-valued stocks and bonds. Along the way, the investigator crosses paths with a femme fatale and silly gangsters.

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.