A pathologist, Dr. Warren Chapin (played by Vincent Price), discovers that the tingling of the spine in states of extreme fear is due to the growth of a tingler—a spinal parasite which can kill the host unless it is destroyed by screaming.
A tectonic shift deep below the Mariana Trench causes a series of ever escalating earthquakes. If a team of leading seismologists fails to stop the disaster, the events will break apart the Earth, resulting in billions of casualties.