War has awakened and every act of violence makes it stronger. The Red Rider has entered the human world. Nations launch attacks against enemies they cannot name, borders collapse, and governments surrender their authority to Calloway's World Unity Authority. Promising peace through unity, Calloway turns humanity against the supernatural kingdoms hidden beneath its feet. Deep beneath Alabama, the ancient City of Evanus prepares for invasion. Zephira, the winged warrior feared by Heaven and Hell alike, stands between humanity and the hidden world. Beside her are Daniel, a human carrying celestial fire within his blood; Vharok, the enormous hellhound bound to her shadow; and an alliance of demons, vampires, werewolves, fae, witches, merfolk, dwarfs, griffins, and fallen angels who have spent centuries distrusting one another. But the Red Rider cannot be defeated with weapons. Every battle feeds him. Every angry thought strengthens his armor. Every attempt to destroy him brings the world closer to endless war. Then ash begins falling inside Evanus. Within it lies the Gospel of Ash an ancient celestial prophecy containing a command capable of erasing entire kingdoms from history. As Calloway uses its words to decide which worlds deserve to survive, Zephira discovers that the prophecy does more than predict her future. It knows her blood, her purpose, and the true name Heaven intends to use against her. To save the living and restore those already forgotten, Zephira must unite enemies who would rather destroy one another, confront the father whose legacy shaped her, and prove that no prophecy not even one written by Heaven has the power to decide who she chooses to become. The Gospel of Ash, Book Three of The City Beneath, is an epic dark-fantasy story of war, memory, mercy, forbidden love, and the choices that make someone a monster or a hero.