Two country handymen, Earl Basset and Valentine McKee, discover that their desolate town of Perfection, Nevada is infested with gigantic man-eating wormlike creatures that live below ground. The slightest vibration caused by movement attract the creatures to attack without warning, exploding out of the ground with jaws opened to swallow with deadly precision. The race is on to overcome these slimy subterraneans as the two unlikely heroes team up with a couple of zany characters, Burt and Heather Gummer, along with a shapely seismology student.