Lydia Meadows, a former lawyer turned full-time mother, is startled to discover that her daughter Erin is one of the popular girls, a tight foursome whose mothers are also great friends. Lydia has always thought of popular girls as ambitious little manipulators who enjoy being cruel. But Erin is kind and well-adjusted. Maybe this popularity thing won't be so bad after all. Then a new student ruthlessly targets Erin to boost her own popularity, and Lydia wonders what to do when her daughter's phone stops ringing. And the uneasiness among the girls begins to affect the friendship of the mothers - even though they are all grown women who should know better. Has their driven energy, once directed toward their careers, turned into an obsession with the social lives of their daughters?