When, at the age of fifty-eight, Joanne learns that Douglas Ellard, the reserved general practitioner whom she had grown up believing to be her father was, in fact, the best friend of her biological father, the brilliant visual artist Desmond Love, she begins to question not just who she is but what factors play a role in shaping all of us and in making us who we really are. Joanne is offered the chance to revisit her family history, when writer Roy Brodnitz, author of The Happiest Girl, a Broadway mega-hit inspired by a Desmond Love painting, approaches her with the idea of making a mini-series about the close relationship between the Ellard and Love families. Brodnitz is in town working on the film adaptation of his Broadway hit, and he and his film company soon become a significant presence in the life of Joanne's family, with results that are both life-changing and menacing. When Joanne and Zack's eighteen-year-old daughter, Taylor Shreve, develops a close friendship with the seventeen-year-old actress starring in the movie, the Shreve family is exposed to the dark side of the film industry and they uncover disturbing truths about the handsome and talented people they have invited into their lives. A darkness of the heart explores the ways in which clear vision, generosity of spirit, and a willingness to love can combat the forces in our world that seek to encroach upon innocence.