A 400-foot (122-meter) dinosaur-like beast, awoken from undersea hibernation off the Japanese coast by atomic-bomb testing, attacks Tokyo.
A treasury agent on the trail of counterfeit money confides to fellow ocean liner passenger, Charlie Chan, that there have been two attempts on his life.
In San Francisco’s Chinatown, Charlie helps two different people search for their missing relatives and uncovers a murder for insurance scheme.