The more effective pairing of "Charlie" (Sidney Toler) and No 2 son "Jimmy" (Victor Sen Yung) are embroiled in an investigation into an apparent suicide of his friend "Paul" (Louis Heydt) on a plane to San Francisco. It soon starts to look like there is much more too it to - the last page of a manuscript he was working on has gone missing - and investigations lead them to the door of the mysterious "Dr. Zodiak" who claims enormous psychic powers. What ensues now is quite a cleverly constructed mystery with loads of mystic hokum, some blackmail and a good supporting cast from the likes of Pauli...