From the author of The Court of the Air and The Kingdom Beyond the Waves comes a thrilling new adventure set in the same Victorian-style world. Perfect for fans of Philip Pullman and Susanna Clarke.Born into captivity as a product of the Royal Breeding House, friendless orphan Purity Drake suddenly finds herself on the run with a foreign vagrant from the North after accidentally killing one of her guards.Her strange rescuer claims he is on the run himself from terrible forces who mean to enslave the Kingdom of Jackals as they conquered his own nation. Purity doubts his story, until reports begin to filter through from Jackals’ neighbours of the terrible Army of Shadows, marching across the continent and sweepign all before them.But there’s more to Purity than meets the eye. As Jackals girds itself for war against and army of near-unkillable beasts serving an ancient evil with a terrible secret, it soon becomes clear that their only hope is a strange little royalist girl and the last, desperate plan of an escaped slave.