Sidney Toler comes up against the supernatural in the form of Zodiac, a possibly phony psychic who is possibly blackmailing people (including one of Charlie Chan's friends) until they commit suicide. The Imdb trivia page suggests that this movie might have provided some inspiration for San Francisco's 1960s Zodiac killer. Huh? But as far as the CC series goes, this is a ripper -- probably one of the best. The cast of potential suspects is better defined (including Cesar Romero as a magician) as is the overall arc of the plot and tightness of the script (even Number Two Son Jimmy's comic relief is kept to a minimum). If it influenced anything, it is more likely to have been "Scooby Doo, Where Are You?"