Not to be confused with "The Mysterious Mr. Wong."
There is actually no mystery of Mr. Wong, unless you're curious why the famous "Oriental" detective-scholar looks like this:
It's a good thing Wong's on the case when a man is shot; the clues are written in that baffling - dare I say inscrutible? - Oriental language:
The "Eye of the Daughter of the Moon" is a gem, and a fellow has bought it even though it has a Terrible Curse. He's shot, of course, and shot in a way they loved to kill characters in 30s and 40s movies: in the middle of playing charades, or acting in a play. Someone uses a stage gun with blanks - we all have one around the house, you know - and eventually someone notices he's actually dead. Wong has to solve the crime, being Wong and all. It moves along at a better clip than most Monogram crapfests, and Karloff is smooth and urbane.
But not a Wong.