The fifth novel in the Twilight of Empire series sees Aurelius Castus caught between loyalty to the Emperor Constantine and the plotting of his son. Aurelius Castus is one of the leading military commanders of an empire riven by civil war, but age is telling upon him. As the emperor Constantine grows ever more ruthless in his pursuit of power, Castus fears that the world he knows is slipping away. On the eve of the war's final campaign, Castus discovers that the emperor's son Crispus aims to depose his father and restore the old ways of Rome. As the armies march, Castus knows that the conflict ahead will be the fiercest he has ever known. With a sadistic torturer on his trail, Castus must choose between honour and survival, and face a final confrontation with the most powerful man in the Roman world, the ruler he has sworn loyally to serve: the emperor Constantine himself.