A 12 episode serial starring Rex, the King of the Wild Horses and Rin-Tin-Tin, Jr. Rex is brought from the island of Sujan, where he is worshiped as a God-Horse, to the U.S. to be trained as a polo pony. He escapes, meets Rinty and with the help of Frank Bradley is returned to Sujan. The natives have been persuaded to turn against their God-Horse, however he is rescued just in time before he is burned as a sacrifice.

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.

A newspaper publisher and his Korean servant fight crime as vigilantes who pose as a notorious masked gangster and his aide.

Cowboys and a businessman compete to find lost treasure.  

A mad scientist tries to sell his formula for a dist integrating gas to foreign powers.

A madman sets out to destroy a group of Chinatown merchants.

Corporal Larry Grant and Sergeant "Mac" McGowan, of the United States Marine Corps, are rival for the love of Frances Schiller, but team up to hunt down "The Tiger Shark," a mad, scientific wizard who is holding Sergeant William Schiller, Frances' brother, a prisoner on a wild, jungle island in the Pacific.

Hank Davis, foreman on a huge dam project, enlists the aid of his two flyer friends when a sinister figure known as The Black Ace leads his Mystery Squadron of masked pilots in an attempt to destroy the dam.