Many years ago, three Hollow sisters disappeared directly from the supervision of their parents. A month later, they appeared in the same place safe and sound. But from that moment on, something changed. Their dark hair turned ashen white, their eyes darkened, and their appetite became simply inhuman. In addition, each had a strange crescent-shaped scar between their collarbones. No one knows the truth about what happened—not even themselves. The Hollow girls are just trying to move on with their lives. But when their older sister, Grace, disappears again, they have no choice: they must face the past and uncover the mystery of their disappearance.