A scientist takes the brain of dead man and revives it via electrodes as it lays suspended in a tank of liquid. Soon, the brain grows to possess enormous psychic powers and inflicts its personality upon the doctor who saved it, creating a "Jekyll and Hyde" paradigm.
A veteran homicide detective who has witnessed his socialite girlfriend kill her husband sees his inexperienced brother assigned to the case.
Mandrake and Lothar battle enemy agents who have kidnapped the beautiful Princess Narda to force the magician to assist them locate a counter-intelligence agent who possess vital information.
A fire worshipping cult of Indian is disbanded by a man, his elephant and tiger.
Captain Braddock of the Los Angeles Racket Squad schools a group of cadet policemen by telling them of three precarious and dangerous cases of con artistry. Included are tracking down a dance hall girl, who, together with a big operative, are thwarted in attempting a robbery; a racketeer fleecing a book publisher on a Trans-Atlantic voyage, and the tripping up of the plans of a phony land syndicate.