It’s a beautiful day in Newport, Rhode Island, when Phoebe Stone arrives at the grand Cornwall Inn. She's immediately mistaken by everyone in the lobby for one of the wedding people, but she’s actually the only guest at the Cornwall who isn’t here for the big event. Phoebe is here because she’s dreamed of coming for years. She hoped to shuck oysters and take sunset sails with her husband. But she’s here without him, at rock bottom, and determined to have one last decadent splurge on herself. Meanwhile, the bride has accounted for every detail and every possible disaster the weekend might yield…except for, well, Phoebe and Phoebe's plan --- which makes it that much more surprising when the two women can’t stop confiding in each other.

For much of her life, Sally Holt has been mystified by the things her older sister, Kathy, seems to have been born knowing. Kathy has answers for all of Sally’s questions about life, love and Billy Barnes, a rising senior and local basketball star who mans the concession stand at the town pool. The girls have been fascinated by Billy ever since he jumped off the roof in elementary school, but Billy has never shown much interest in them until the summer before Sally begins eighth grade. Sally spends much of that summer at the pool, watching in confusion and excitement as her sister falls deeper in love with Billy --- until a tragedy leaves Sally’s life forever intertwined with his.