The Offspring — J.N. Williamson

In a huge house in a suburb of a midwestern city live a little girl named Peg, her older brother Eric, their beautiful mother, distinguished grandfather - and one other. Like Eric and Peg, the fifth member of the family is Elizabeth Porter's child, but there the resemblance ends. For this child was conceived thousands of years ago. It is a child of infinite cunning, infinite evil, an evil as old as time. Its powers are beyond the capacity of men's minds to comprehend or control. If it is not destroyed, one day it will rule the world. THE OFFSPRING: If anything can stop it, it has yet to be born.