The mortal will destroy the primus and free the souls if she does not lose hers first. Rome, 64 AD. The young servant of the temple, Cassia, knows who is responsible for the death of her friends. When a girl, immune to demonic forces, is given the opportunity to challenge her opponent, the great Janus, she agrees without hesitation. She needs to enter his personal chambers as a slave and steal one of the vessels in which he stores souls. But all plans are ruined when Belial appears - a promising devil with an irresistible smile and Janus's main rival. Cassia does not yet suspect that she is about to find herself in the center of the most dangerous battle. Battles for her soul.