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.
Warner Oland
as Charlie Chan
Keye Luke
as Lee Chan
John McGuire
as Hal Blake
Shirley Deane
as Louise Norman
Francis Ford
as John Gaines
J. Carrol Naish
as Tom Holt
Paul Stanton
as Joe Kinney
Boothe Howard
as Dan Farrell
Drue Leyton
as Nellie Farrell
Wade Boteler
as Lt. Macy
Shia Jung
as Su Toy
George Brasno
as Colonel Tim
