Vincent Price stars as an obsessed doctor who discovers that fear manifests itself as a parasitic creature, which grows on the spinal cords of terrified people. If they scream, the Tingler can be destroyed. If they don't, it will sever the spinal column and kill them. He successfully isolates and removes the Tingler from a deaf mute (Judith Evelyn) who has been scared to death by her devious husband. Once captured, the Tingler escapes and runs amok in a crowded movie theater. Terror is loose, but can it be stopped?