Mild mannered zoology professor Dr. David Huxley is excited by the news that an intercostal clavicle bone has been found to complete his brontosaurus skeleton, a project four years in the construction. He is equally excited about his imminent marriage to his assistant, the officious Alice Swallow, who is interested in him more for his work than for him as a person. David needs the $1 million endowment of wealthy dowager Mrs. Carleton Random to complete the project. Her lawyer, Alexander Peabody, will make the decision on her behalf, so David needs to get in his favor. However, whenever David tries to make a good impression on Peabody, the same young woman always seems to do something to make him look bad. She is the flighty heiress Susan Vance. The more David wants Susan to go away, the more Susan seems not to want or be able to. But David eventually learns that Alexander Peabody is her good friend...

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...