Dr. Henry Jekyll experiments with scientific means of revealing the hidden, dark side of man and releases a murderer from within himself.

'Firebrand' Jordan is a ranger sent into the high Sierras to assist the local Sheriff Ed Burns in capturing a mysterious band of counterfeiters.

Terry Macy (Reed Howes), the son of a newspaper's founder, is assigned to investigate a mysterious warning signed '30' (newspaper term for 'The End)that has been sent to a local politician. Terry is captured at a clandestine meeting of the 'Mystic Medicants", an outlaw band, where he overhears the plans of a plot to kill his uncle, Robert Macy, publisher of the newspaper. Terry must also, according to his father's will, get married within a short period of time is he is to inherit the newspaper.

After Tarzan's estate is destroyed by Arabs Jane is sold into slavery by a man posing as a friendly scientist. Tarzan develops amnesia after a blow to the head. When he recovers his memory (from a later blow) he defeats the villain, recovers the fabulous jewels of Opar, and rescues Jane.

Vacationing in the Canadian Northwest, a playwright and a songwriter both fall in love with Marie Cleste and take her back with them to New York when her father and her sweetheart apparently die in a forest fire. (The father did perish; the sweetheart escaped, crippled, with his blinded Indian guide into the forest to hide his infirmities.)

Before a planned African expedition, a man's fiancée worries her father's guest plans to steal one of her father's rubies. The couple are kidnapped and held prisoner at a mysterious, creepy house. Strange things are afoot at Satan's house.

A father throws his daughter out of the house when she marries a man he doesn't approve of. In addition, she also finds herself being lusted after by the sinister owner of an opium den.

The naïve Sheila Fairfax (Brent) plays with men’s emotions without fully comprehending the risks leading to several dangerous situations from which she and the man she loves to barely escape with their lives.

15 chapter adventure serial starring Doris Kenyon. Episode titles: 1. The Gauntlet of Death 2. Counterfeit Faces 3. The Island of Dread 4. The False Locket 5. The Air-Lock 6. The Flower of Death 7. The Fire Trap 8. Slide for Life 9. Jets of Flame 10. Cogs of Death 11. Trapped by Treachery 12. Eyes in the Wall 13. Jaws of the Tiger 14. The Unmasking 15. The Girl of the Prophecy.

Ruth Earlton has come home to her ancestral mansion to claim her inheritance. Accompanied by her boyfriend, she discovers that her father died suddenly under suspicious circumstances. Now it's her turn, as her deranged and relentless uncle targets her for death with the help of his wife and son, plus a very unhappy ape.