The Fifth Child by Doris Lessing

Four children, a beautiful old house, the love of relatives and friends – Harriet and David Lovatt’s life is a glorious hymn to domestic bliss and old-fashioned family values. But when their fifth child is born, a sickly and implacable shadow is cast over this tender idyll. Large and ugly, violent and uncontrollable, the infant Ben, ‘full of cold dislike’, tears at Harriet’s breast. Struggling to care for her new-born child, faced with a darkness and a strange defiance she has never known before, Harriet is deeply afraid of what, exactly, she has brought into the world …

(HarperCollins)