Sixty-one-year-old Meredith Taylor answers her door to find a worried-looking little girl, who announces, "I've come to stay with you for a while...I'm your granddaughter." From this unexpected and jaw-dropping event, Meredith and her husband Andy are thrown into an emotional storm. But the turmoil that this little stranger's appearance causes for them pales by comparison to what their unsuspecting son, Aaron, endures. What happens next is a series of revelations and shocking discoveries about Sam's conception and her mother's manipulation, not just of Aaron but of his whole family. Somehow though, in the midst of the rising pressure and the dizzying complications, six-year-old Sam manages to win Meredith and Andy's hearts, even as they watch their own beloved son falling apart emotionally. Part-mystery thriller, part-affecting romance, and part-testament to the power of family love. A Critical Human Error is a book for grownups, who will relate to these complex people and the white-hot emotional conflicts they face.