Enjoyable if less that competent mystery with Boris Karloff once again playing Hugh Wiley's Oriental detective Mr. Wong of San Francisco. Karloff breathes most of the life this film has which tells of a wealthy man and his less than devoted wife and his burgeoning collection of rare and valuable Oriental artifacts - most recently the rarest gem of all, the Eye of the Moon. A dinner party is thrown with Wong and another famous criminologist in attendance. Prior to party games, Mr. Wong is shown the rare gem and a letter he has written with the name of who he suspects of a possible future crime - his murder. The games begin and the wealthy man is shot and Mr. Wong, Mr. Janney(the other criminologist), and the policeman Street(played by Grant Withers)begin to sift through the evidence and see who is the killer(naturally the letter was taken by someone so the movie could go on). While it is true that some of the clues in finding the killer are NOT presented to us, I had no problem at all figuring out who the killer was. Just listen to the conversation between Mr. Wong and the victim carefully and it will resonate loud and clear for you. That being said, I did enjoy this film as the mystery is paced well, there are plenty of red herrings that MIGHT have shaken my preconceived notions, the acting is uniformly pretty good all around, and production values are high for a Monogram Studio release.