Roger Girard 博士是一位富有的科学家,负责进行头部移植实验。他的看护人有一个儿子丹尼,虽然他已经长大成人,但他有孩子的心。一天,一名逃脱的精神病杀手闯入吉拉德的家,杀死了丹尼的父亲,然后被枪杀。随着疯子的死去,丹尼对父亲的死深感不安,吉拉德博士决定采取最后一步,将凶手的头移植到丹尼的身上。
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.