Sarah Macmillan always puts family first, but she can't quite stretch her arms wide enough to hold on to everyone as they all age: her career-minded, inattentive younger sister, Glennie; their grandparents, who are slowly fading; or a pregnancy Sarah desperately wanted. But it's her tumultuous relationship with Glennie that makes Sarah feel the loneliest. She'd always believed that their relationship was foundational, even unbreakable. Though blessed with a happy marriage to Al, whose compassion and humor she admires, Sarah shoulders both caregiving and loss largely alone and grows bitter about Glennie's absences, until one decision forces them all to decide what family means-and who is family. Narrated by the chorus of their three voices, this elegantly told and deeply moving novel examines the pull of tradition, the power of legacies, the importance of forgiveness, and the fertile but fragile ground that is family, the first geography to shape our hearts.