It is the late 19th century and a mysterious airship orbits through the foggy skies. Its terrible secrets are sought by many, including the Royal Society, a fraudulent evangelist, a fiendish vivisectionist, an evil millionaire and an assorted group led by the scientist and explorer Professor Langdon St. Ives. Can St. Ives keep the alien homunculus out of the claws of the villainous Ignacio Narbondo?