World renowned archeologist Dr. Benton returns from Mongolia with a mysterious scroll and immediately dies a horrible death by poison while delivering a lecture. Detective Jimmy Wong (Keye Luke) is called in to solve the case. With the help of Captain Street (Grant Withers) and Benton's beautiful secretary (Lotus Long), Jimmy becomes a human decoy to set a trap for the killer. This is the sixth and final episode of Monogram's Mr. Wong series featuring the Asian detective. Originally conceived for Boris Karloff, the script was rewritten for a younger actor, and presented as a prequel to the five previously released films. Keye Luke, best known for his portrayal as Charlie Chan's Number One Son, appears in what is his only starring role.