Samantha Ranvali can't sleep. Haunted by nightmares and the memory of a man who attacked her years ago, she seeks a cure for her insomnia through an experimental study called "Endymion's Circle." The treatment seems to be a success, but after her first full night of sleep in months, Samantha learns that one of the other participants in the study has been murdered. The body is found crucified upside down, and a recording of J. S. Bach's "Goldberg Variations" plays at the scene. As an old lover investigates the crime, he draws Samantha into a mystery that spans over two hundred years and suggests something far more sinister than the police expect. And with each night of Samantha's newfound sleep, she awakens to another ritualistic crime. Every clue takes her deeper into her own past, her own history of loss, pain, and desperation. Every murder reveals that a dark curse has taken hold of her world. And every clue brings her closer to the revelation that she is the next victim....