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.

Charlie Chan's investigation of a blackmail-induced suicide as a case of murder leads him into a world of magick and mysticism peopled with a stage magician, a phoney spiritualist, and a for-real mind reader.

Chan, in Paris for a reunion with friends from World War I, becomes involved in investigating the murder of a munitions manufacturer who was supplying arms to the enemy, even as the rising clouds of World War II force the city into nightly blackout status..

While investigating the theft of antiquities from an ancient tomb excavation , Charlie discovers that the body of the expedition's leader concealed inside the mummy's wrappings.

Charlie Chan is sought out by Pamela Gray, a desperate young socialite whose brother Paul awaits execution for the murder of a weapons inventor. Pamela is convinced of his innocence.