Her by Harriet Lane
Emma and Nina seem to have nothing in common. Emma is a harried mother who has put her career in television on hold for motherhood. Nina’s one child is a teenager and she has a successful career as a painter. One day Nina finds Emma’s wallet and returns it to her in her home and an unlikely friendship blossoms. Or does it?
The book is told in alternating chapters from each of the two main characters point of view. From the beginning you know that Nina knows Emma, remembers her from her teen years, but that Emma does not recognize Nina. You also know that Nina loathes Emma and wants to get back at her for something that happened between them as teenagers, but you don’t know what happened until almost the end of the book. A frightening look at how one person’s actions, even in ignorance, can upend the life of another and how hatred can build into something irrational and evil over time.