A mysterious Chinese woman arrives at Charlie Chan’s home and is murdered there shortly afterward. The only clues are the ring with which she introduced herself, and the message “Capt K” she scrawled before dying.
Joaquin Shannon confesses to a murder he didn’t commit. He gets a year in prison to start for manslaughter. It gets hard to be on good behavior.
The Society of the Black Dragons sends Bela Lugosi (Dr. Melcher) to transform 6 japanese into indentical likenesses of American industrialists forming a 5th column. This is at the behest of the Nazis.
Nick Allen comes to the rescue when a gun moll Jo Elliot gets hassled on the street. Spudsy, Red and Jo take it on the lam and Nick ends up going along. They get stranded because of car trouble and end up staying with old, blind Pop Regan. After weeks with Pop Regan, all of them seem to like the rural lifestyle better and start to think about going straight.