Sandy Pressman is a nice suburban wife whose boredom is getting the best of her. She could be making friends at the club, like her husband keeps encouraging her to do. Or working on her golf game. Or getting her hair done. But for some reason, these things don't interest her as much as the naked man on the motorcycle.

Margaret Simon, almost 12, has just moved from New York City to the suburbs, and she’s anxious to fit in with her new friends. When she’s asked to join a secret club, she jumps at the chance. But when the girls start talking about boys, bras, and getting their first periods, Margaret starts to wonder if she’s normal. There are some things about growing up that are hard for her to talk about, even with her friends. Lucky for Margaret, she’s got someone else to confide in...someone who always listens.

When Deenie finds out that she has scoliosis, she’s scared. When she sees the brace for the first time, she wants to scream. But the words won’t come out. And Deenie, beautiful Deenie, who everyone says should be a model, is stuck wearing a brace from her neck to her hips. For four years—or longer. She never worried about how she looked before—how will she ever face the hard times ahead?

In the summer of 1977, Victoria Leonard’s world changes forever when Caitlin Somers chooses her as a friend. Dazzling, reckless Caitlin welcomes Vix into the heart of her sprawling, eccentric family, opening doors to a world of unimaginable privilege, sweeping her away to vacations on Martha’s Vineyard, an enchanting place where the two friends become “summer sisters”. Now, years later, Vix is working in New York City. Caitlin is getting married on the Vineyard. And the early magic of their long complicated friendship has faded.

Margo and B.B. are each divorced, and each is trying to reinvent her life in Colorado - while their respective teenage daughters look on with a mixture of humor and horror. But even smart women sometimes have a lot to learn - and they will, when B.B.’s ex-husband moves in next door to Margo.