Mina, an agent of industrial espionage, is hired to investigate the secretive hidden project of a powerful industrialist.
Following the trail to Project Charybdis, she finds an underwater world where female fulfil the lusts of others, unable to escape as they are transformed into latex-bound mermaids and pets.
Having blundered into the project, Mina joins the rubber-encased ranks of the deep-sea harem. There she finds new pleasure in her strict captivity as she surrenders herself to those she had been sent to expose.