After her adventures with the necromancer in Istanbul, Nadira, now a necromancer herself and the new High Priestess of Elysium, sets out on a journey with her companions to Persia to meet with a mysterious power that dwells in the mountains of Arborz. She intends to learn the secrets of Zoroaster and claim for herself the power over the realms of the dead. She and her companions meet up with the secret remnants of the Nizari Ismaili Assassins and the Sufi mystics who present Nadira with the Books of the Dead to take back to Eleusis. She hopes these books contain what she needs to be able to stop the European powers from igniting a new crusade to reclaim Istanbul and Jerusalem from the Turks. As she becomes more powerful, she begins to lose what it means to be human and starts to take on the guise of a goddess. Her companions wonder if she is becoming an angel of mercy, or a frightening reaper of souls.