Although his murdered friend was by all accounts a scoundrel a true "bounder" Edward Wales is determined to trap his killer by staging a seance using a famous medium. Many of the 13 seance participants had a reason and a means to kill, and one of them uses the cover of darkness to kill again. When someone close to the medium is suspected she turns detective, in the hope of uncovering the true murderer.

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...

A circus' beautiful trapeze artist agrees to marry the leader of side-show performers, but his deformed friends discover she is only marrying him for his inheritance.