In the small seaside town of Palmetto Beach, the Sheffield sisters -- responsible Riley, vivacious Maisy, and fun-loving Adalee -- reunite to celebrate their mother's birthday and try to save the family bookstore, which has long been a beloved gathering place in their tight-knit community. But June also marks the return of Mack Logan, who thirteen years ago was Riley's best friend and Maisy's teenage crush. His choice of Maisy over Riley during that pivotal summer destroyed the special closeness between the sisters, and sent their lives in very different directions. Now Riley, a single mom who doubts any man will ever live up to the ideal Mack Logan, must work with her sisters while hiding a shattering secret about their mother. Maisy, a California designer, still blames Riley for ruining her one true love. And Adalee, a college coed, resents the family's intrusion into her summer plans. When Mack arrives, all three sisters are forced to confront their long-held beliefs about the conflicts that tore them apart and the bonds of love and loyalty that still draw them together. Will they allow the past to define the future?