After feeding golden griffin Helior with her blood for ten years, Octavia is betrayed and killed by him and her sister Josephine. Reborn on their bonding day, she gives Helior to Josephine and chooses a dying black hatchling instead. He is Umbrathis, an abyssal black dragon who helps her grow stronger. As Helior turns to forbidden magic, Octavia exposes Josephine’s lies, defeats the beast that once consumed her, and learns that a true bond means standing as equals.
