What could lead a parent to kill a child? Dutch author Renate Dorrestein tries to answer that chilling question in her new novel "A Heart of Stone" The book centers on Ellen, whose mother murdered Ellen's father and siblings before killing herself. Ellen struggles to understand why her mother committed such a horrendous act and why she alone was spared. Dorrestein told Minnesota Public Radio's Stephanie Curtis she was inspired to write the novel four years ago, when a series of murder-suicides within families shocked the Netherlands. She says most of the cases involved husbands and wives caught in bad divorces or violent arguments, but one stood out from the others.