In 336 AD, Constantine leads the Roman Empire, and Christianity has become the official religion. Arius, accused of heresy after the council of Nicea, has regained the emperor's favor. But when he goes to receive the communion that will reintegrate him into the Church, he dies under mysterious circumstances. Gratus has been called upon by the emperor to investigate the death before it destroys the newly formed Church, but he must battle Constantine's demons as well as his own in order to solve the mystery. "En 336 AD, Constantino gobierna el imperio romano y el cristianismo se ha convertido en la religion oficial. Arrio, acusado de herejia tras el concilio de Nicea, ha recuperado el favor del emperador. Pero cuando se dirige a recibir la comunion que lo reintegrara en el seno de la Iglesia, muere en extranas circunstancias. Grato es llamado por el emperador para investigar esta muerte antes de que destruya la Iglesia recien constituida, pero tendra que combatir los demonios de Constantino al igual que los suyos para poder resolver el misterio."