Con artist Marilyn Fryser (Joan Collins) has a steady and profitable racket. Along with an unscrupulous ship captain (Robert Lansing), she takes naive investors on cruises of the Everglades and persuades them to invest in a worthless housing development. But when she and her latest group of potential customers go ashore on a small island, they're horrified to discover that illegally dumped nuclear waste has created a breed of giant ants bent on human destruction.