The terror began the very first night that Dan Post spent with his children in the old house on the hill. In his sleep he felt his identity dissolving, merging with human beings of the distant past, creatures who had somehow returned to life as they invaded his defenseless mind. At first Dan Post thought he was going mad. Then he discovered the truth about the house that he and his children lived in ... what waited for them at the end of the tunnel behind the basement wall ... And Dan Post could only wish that he was mad ... that the nightmare was only a dream that the horror was not inescapably real...