Seraphine Voss owns three copper coins, a cellar she shares with orphans, and a birthmark she has never been able to see — a pale, six-pointed star on the nape of her neck that no one has ever explained. Until the night a vampire prince watches her from the shadows of a night market and does not look away. Prince Caelan Ashvorne of the ancient House of Dusk has spent two years searching for the girl of a dying oracle's prophecy — the Ash Girl, born of no crown and no consequence, whose blood is the only antigen in existence for a seven-hundred-year curse rotting the roots of their world. He expected to find a tool. He found Seraphine instead, and the difference is proving to be a problem. Prince Lucian of the rival House of Dawn found her the same night. He is warmer. Easier. The kind of dangerous that arrives with a smile already in place. Both want her at their court. Both are carrying half a prophecy and calling it the whole truth. And somewhere beneath the careful rivalry of two kingdoms, a third secret has been buried — one that neither prince knows, that changes everything about what the cure actually requires, and what it will cost. Seraphine has survived twenty years by being invisible. She is about to discover what happens when the world can finally see her — and when the mark on her neck starts answering back. She came to them as a nobody from the lower quarters. She will not leave the same thing she arrived as. Neither will they.