When a young friend of Charlie Chan's, mystery writer Paul Essex, receives a strange message on the flight to San Francisco connected with 'Zodiac', and before the landing strangely commits suicide, Charlie feels it his duty, of course, to find out who drove him to kill himself - because, as he remarks in a conversation about the occult: black magic very often goes with blackmail...
He's invited to 'Treasure Island', part of the San Francisco World Fair, by magician Rhadini, who soon reveals that his great antagonist is - 'Mr. Zodiac'! So Charlie knows he's on the right track, especially since strange things keep happening: Essex' last script, 'The Mystery of the Pigmy Arrow', which he'd just finished on the plane, vanishes, and Charlie and son Jimmy suspect ominous 'Mr. Gregory', allegedly an insurance agent. At 'Treasure Island', they meet again; and we also get to know quite some other illustrious characters: Eve Cairo, who possesses REAL psychic powers as a mind reader and for some reason seems to believe very much in Dr. Zodiac's abilities - a fact of which her boyfriend, police reporter Pete Lewis, disapproves greatly; then there's Bessie Sibley, a reckless man-hunter, who seems quite fond of Rhadini, which in turn makes his wife Myra (a former knife thrower from vaudeville) pretty jealous...
Charlie finally manages to be granted entrance to Dr. Zodiac's house, who gives a 'performance' of his psychic abilities, communicating in a really eerie dark room séance through an ancient Egyptian priestess with Paul Essex, who declares that he hadn't been blackmailed - but Charlie is convinced otherwise. So, he returns to the house when he knows that Zodiac is out; and actually finds, hidden in a secret room behind a huge safe, a whole filing cabinet with files full of ideal blackmail information on people from all over the country! He sets the whole room on fire to destroy once and for all Zodiac's 'income source' - and then thinks of a clever way to expose the ruthless blackmailer publicly: he suggests to Rhadini to challenge Zodiac to a 'spiritual duel'...
This is certainly one of the VERY best entries in the 'Charlie Chan' series, most magnificently and literally hauntingly photographed, and marvelously acted (guest starring as 'Rhadini' is none less than one of the great matinée idols of the 30s, Cesar Romero!) - the atmosphere in this movie is so fascinating that you can't take your eyes off the screen even for a moment. And yet, amid all those creepy, murderous ongoings there is always room for some humor: Jimmy Chan, as always eager to help his Pop, rushes onto the stage for an announcement - and grabs Rhadini's 'magic' coat, which starts producing flowers, ribbons and rabbits while he's trying to make his speech! There's really NOTHING missing in this magnificent thriller...
