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 teenager who stops off to see his dealer to test a new drug before heading off for a night of partying. On the way home, he picks up an injured woman and the night takes a surreal tur