A massive earth tremor opens a deep crevasse in the California dessert, releasing a bizarre and deadly breed of foot-long cockroaches which threaten to destroy the city of Riverside before spreading across the country. Entomologist Bradford Dillman tried to find a way to deal with these virtually indestructible creatures. The roaches also seem to have a high intelligence which makes Dillman's task nearly hopeless. This is a creepy crawler right out of the worst nightmare!