An evil Mermaid falls in love with Marina's fiancé Roman and aims to keep him away from Marina in her Kingdom of Death under water. The Mermaid is a young woman who drowned a few centuries ago. Marina only has one week to overcome her fear of the dark water, to remain human in the deathly fight with the monsters and not to become one herself.
Two carnies (Sewell and Gugino) abduct a mermaid in Ireland, circa 1900, and decide to transport her to America. As their ship loses its way and heads towards the mythical Forbidden Islands, the mermaid begins to display its deadly side.
A dangerous combination of radiation and insecticide causes the unfortunate Scott Carey to shrink, slowly but surely, until he is only a few inches tall. His home becomes a wilderness where he must survive everything from spiders living in the cellar to his beloved cat.