Good Harbor is the long stretch of Cape Ann beach where two women friends walk and talk, sharing their personal histories and learning life's lessons from each other. Kathleen Levine, a longtime resident of Gloucester, Massachusetts, is maternal and steady, a devoted children's librarian, a convert to Judaism, and mother to two grown sons. When her serene life is thrown into turmoil by a diagnosis of breast cancer at fifty-nine, painful past secrets emerge and she desperately needs a friend. Forty-two-year-old Joyce Tabachnik is a sharp-witted freelance writer who is also at a fragile point in her life. She's come to Gloucester to follow her literary aspirations, but realizes that her husband and young daughter are becoming increasingly distant. Together, Kathleen and Joyce forge a once-in-a-lifetime bond and help each other to confront scars left by old emotional wounds.