Libby is the protagonist. She is 31 years old and petite in stature. Her defining physical characteristic is her bright red hair, which is dyed blond for most of the novel. Her hair color is significant because it is a family trait, which she shares with her mother, brother, and younger sister. Libby is the survivor of a terrible tragedy, the murder of her family, which happened when she was seven. Since then, the trauma of witnessing that event and her guilt over testifying in court against Ben have overshadowed her life.

After the murders, Libby became a child celebrity. Throughout her childhood and young adult years, this forced her to play the role of the victim whose primary skill was eliciting sympathy from others. This ties her to the theme of The Objectification of Victims in True Crime Culture from an early age. She wrote an unsuccessful self-help book called Brand New Day! about how to move on from childhood trauma, but in reality, the murders are a constant presence in her life. She describes her memory of the murders as Darkplace, a psychological state in which she relives the horrors of that night.