After humanity's first manned mission to the Red Planet was lost, a second expedition arrives. The explorers prepare to exterminate the cockroaches that were used to transform the Martian environment, but are shocked to discover that the insects have mutated into giant, aggressive humanoids with one overriding goal - exterminate the humans! However, this crew of explorers has each undergone the "Bugs Procedure," terrifying experimental surgery designed to make them more than human...