Persepolae has fallen.Karnopolis has burned.As the dark forces of the Undead sweep across what remains of the empire, Nazafareen must obey the summons of a demon queen to save Darius's father, Victor. Burdened with a power she doesn't understand and can barely control, Nazafareen embarks on a perilous journey through the shadowlands to the House-Behind-the-Veil. But what awaits her there is worse than she ever imagined…A thousand leagues away, Tijah leads a group of children on a desperate mission to rescue the prisoners at Gorgon-e Gaz, the stronghold where the oldest daevas are kept. To get there, they must cross the Great Salt Plain, a parched ruin occupied by the armies of the night. A chance encounter adds a ghost from the past to their number. But will they arrive in time to avert a massacre?And in the House-Behind-the-Veil, Balthazar and the Prophet Zarathustra discover that they have more in common than meets the eye. But is it enough to salvage the necromancer's bloodstained soul and thwart his mistress's plans?As a final showdown looms between Alexander the Great and Queen Neblis, the truth of the daevas' origins is revealed and three worlds collide in this thrilling conclusion to the Fourth Element series.