What makes a wife a lover?For Kate, the spark went out of her marriage long ago but her husband doesn't seem to notice. Their role as parents consumes their lives so they need to rekindle the romance they once shared.What makes a woman a mother?For Jo, a high-powered career has led her to believe that she doesn't have a single maternal instinct. When an orphan unexpectedly enters her life, she is forced to confront her own unhappy childhood and the walls it has built around her heart.What makes a man the love of your life?For Sarah, home is the steamy jungles of Africa while the man of her dreams waits in the air-conditioned confines of Los Angeles. Her longing for this man from the past is blinding her to a new love standing right in front of her.What these women all have in common is a friend with a generous soul, an irrepressible spirit- and a serious illness. In her final letters, Rachel raises one last question: What makes a friend live in our hearts forever?