Lumsden Moss is an escaped thief and an unrepentant bibliophile with a long-suffering desire to foist some karmic retribution on those who have wronged him. But when the opportunity to steal a rare book from the man who sentenced him to prison puts him on the wrong side of the wrong people, Moss finds himself on the run. And it's not just the book he stole that these people want, it's also the secrets of a long-forgotten location on Nightjar Island, a place cursed and abandoned since the Purge. When Moss falls in with Imogene, a nimble-fingered thief who has taken a traveling bookcase filled with many secrets, he starts to realize how much of his unsavory past is indelibly tied to a frightening witch-child and her nightmarish pet monster. In a fantastic world, still recovering from a war where magic and technology were fused together, Moss and Imogen must decipher the mystery of their mutual pasts in order to illuminate the dark heart that still lurks on Nightjar Island.