Two sailors get caught in a mountain of mix-ups when they meet their long-lost twins. Laurel and Hardy play themselves and their twins.

While visiting the circus with his family, Charlie is recruited by the big top's co-owner to investigate threatening letters that he's received.

Paul Manderley, eccentric historian, and his wife, descendant of the Borgias, live in an isolated castle-like mansion in the Mojave Desert. When a guest suddenly collapses, Charlie Chan is invited to stay. As the standard mystery-mansion props come into play, and all means of outside communication are sabotaged, it becomes evident that...

A pair of murders in Rio de Janeiro leads the local police to call the famed detective. Charlie is puzzled, at first, when it appears that one of the murderers is killed by the first victim's widow.

When Charlie's old friend from Scotland Yard is murdered when they attend a police convention in New York, Chan picks up the case he was working on.