The latest novel from Sara Shepard, author of Reputation and the number one New York Times best-selling Pretty Little Liars series. When the principal of an elite California preschool is attacked, three moms - who feel like outsiders among the school's manicured and ultra-wealthy community - must work together to uncover what she's hiding, figure out who's trying to frame them, and make sure their own secrets stay hidden.

Andrea, Lauren, and Ronnie all see themselves as good, loving moms who are trying their best, but they each arrive at the Silver Swans preschool Welcome Breakfast with something to hide. Andrea is running away from a past on the East Coast, which she cannot afford for the other parents to discover. Lauren is recovering from a postpartum condition her husband has warned her not to disclose. And Ronnie is hiding herself and her daughter from the one man who could at any moment appear in their lives and ruin everything she holds dear. They already feel like impostors among the school's community of polished parents. But then notes appear in their children’s backpacks after the first day at school. Notes that indicate that someone knows their deepest, darkest secrets and needs them gone. Does someone not want them in the community? Or is it something more menacing - does someone know everything?

When the principal of the school is the victim of an almost-fatal attack, it quickly becomes clear that the Silver Swans community is not as flawless as the brochures and website would have you believe. The three moms must band together to uncover the school's many secrets before the other suspicious parents and town police close in and use their outsider status to blame them...and before they lose what they have worked so hard for.