Saskia returns to Ivory Hall to train in bone magic, determined to stop Latham from gaining the power of all three Sights - past, present, and future. But danger lurks within the fortress's marrow. Trials are underway for the apprentices, and the tasks feel specifically engineered to torment Saskia, which is exactly what Latham wants.

As she grows increasingly more suspicious, her thirst for revenge becomes all-consuming. Together with the friends she can trust and the boy she loved in another lifetime, Saskia traces clues from Latham's past to determine what he'll do next. Their search leads them across Kastelia and brings them to a workshop housing a vast collection of horrors, including the bones Latham stole from Gran, and the knowledge that the future isn't all that's in jeopardy - but the past as well.