Both Sam Crew and his gang and Sonora Joe and his men are rustlers after a cattle herd just arriving. John Steele, sent by the Governor, is out to stop them. Greatly outnumbered, Steele's plan is to deputize Sonora and his men to fight the Crew gang.

After his ship goes down, Edward Parker is rescued at sea. Parker gets into a fight with Captain Davies of the Apia and the Captain tosses him overboard while making a delivery to the tiny tropical island of Dr. Moreau. Parker discovers that Moreau has good reason to be so secretive on his lonely island. The doctor is a whip-cracking task master to a growing population of his own gruesome human/animal experiments. He does have one prize result, Lota the beautiful panther woman. Parker's fortunes for escape look up after his fiancée Ruth finds him with the help of fearless Captain Donohue. However, when Moreau's tribe of near-humans rises up to rebel, no one is safe...

Although innocent, reporter Frank Ross is found guilty of murder and is sent to jail. While his friends...

Two drifters are passing through a Western town, when news comes in that a local farmer has been murdered and his cattle stolen. The townspeople, joined by the drifters, form a posse to catch the perpetrators. They find three men in possession of the cattle, and are determined to see justice done on the spot.