A disease carried by common cockroaches is killing Manhattan children. In an effort to stop the epidemic an entomologist, Susan Tyler, creates a mutant breed of insect that secretes a fluid to kill the roaches. This mutant breed was engineered to die after one generation, but three years later Susan finds out that the species has survived and evolved into a large, gruesome monster that can mimic human form.
A lonely waitress with a tragic past, Agnes rooms in a run-down motel, living in fear of her abusive, recently paroled ex-husband. But when Agnes begins a tentative romance with Peter, an eccentric, nervous drifter, she starts to feel hopeful again - until the first bugs arrive...