You Should Have Known

 is a novel written by Jean Hanff Korelitz. It was published in March of 2014. The HBO miniseries, The Undoing, is based on this book.

Summary
Grace Reinhart Sachs is living the only life she ever wanted for herself, devoted to her husband, a pediatric oncologist at a major cancer hospital, their young son Henry, and the patients she sees in her therapy practice.

Grace is also the author of You Should Have Known, a book in which she castigates women for not valuing their intuition and calls upon them to examine their first impressions of men for signs of serious trouble later on. But weeks before the book is published, a chasm opens in her own life: a violent death, a missing husband, and, in the place of a man Grace thought she knew, only a chain of terrible revelations. Left behind in the wake of a spreading and very public disaster and horrified by the ways in which she has failed to heed her own advice, Grace must dismantle one life and create another for her child and herself.