A gathering of the members of the Hot Flash Club at The Haven, an exclusive spa, is turned upside down when Shirley announces her new financial partnership with a much younger boyfriend.

Lily Fox, the baby of her family, sends her sister Abbie urgent emails begging her to return home to Nantucket. Their middle sister, Emma, has taken to her bed, emotionally devastated after the loss of her high-powered stockbroker's job and a shockingly unexpected break-up with her fiancé. Also, Lily is deeply worried that Marina, the beautiful, enigmatic woman renting their guesthouse, has set her sights on the sisters' widowed father, Jim.