Robert Claybourne breaks with the crusade and and meets with Sultan Beyazid, accepting responsibility for the defense of the holy city of Sion against the crusaders.
In Myrridia, the capital city prepares defenses against an expected papal attack. Edward Fitzroy and Allyson Claybourne make their own preparations: to go on the offensive against the papal triumvirate. With the help of another Magical practitioner, they battle the three popes, each channeling powers much greater than their own, prepared to pay the ultimate price, if needed.
While this battle ensues, Rhennsbury is put under siege and the castle is attacked with a toxic botanical, putting everyone in mortal danger. Magical practitioners remaining in the city work frantically to find a way to remove the invisible barrier erected around the castle before all perish.
In Sion, the crusaders attack, using Magical and mundane methods, and the city responds in kind.
Ultimately, the battle for possession of the city rests in a Magical duel, including a fight to the death between two siblings ñ Jared and Breanna Carpenter.