From publisher blurb:
For 800 years the Jinn Lands were the center of a vast, aggressive, magic-rich empire. For 800 years they were the home of countless slaves, forced into servitude by their unearthly masters. But now they are a land of blasted ruins and distant memories, of lone caravanserais and remote oases. Although their cities are gone, reduced to dust by the rebellious slave, the jinn still lurk here in small numbers, patiently waiting for the day they will unleash their vengeance.
This supplement explores the origins of the jinn and the atmosphere of their homeland, expands the cult of Shamash with guidelines for clerics and important festivals, provides six new locations to explore and three major NPCs with whom heroes can interact, details two new cults, and provides stats for the fearsome greater jinn.