Sensible thirty-six-year-old Sophie Anderson has always kwn what to do. She kws her role in life: the supportive wife of a successful architect and calm, capable mother of two. But on a warm summer night, as the house grows quiet around her and her children fall asleep, she wonders what's missing from her life. When her husband echoes that lonely question, anuncing that he's leaving her for ather woman, Sophie realizes she has idea what's next. Impulsively renting a guest cottage on Nantucket from her friend Susie Swenson, Sophie rounds up her kids, Jonah and Lacey, and leaves Boston for a quiet family vacation, minus one.