Ok, so I'm thinking of a big campaign arc soon involving the Azer making a play to depose the Efreet Sultan and reclaim the City of Brass, which they built. I run a 2 man party, my brother and his roommate, 14th level, and climbing, Warlock and Paladin. Recently we had a cool adventure where some Azer hired them to retrieve something called "The Heart of Fire", which turned out to be a really powerful Azer, who is in fact their leader but the PC's don't know how important he is.

The Azer basically have secretly built giant forges, almost like modern factories, but needed the fires of their leader and his skills to make them work properly, and have been cranking out armies of Animated Suits, Helmed Horrors, and Iron Golems, as well as enlisting allies from the many, MANY enemies the Efreet have made in their centuries of conquest and enslavement, allies who wish to see an end to the tyranny and depredations of the Sultan and his satraps. After all these years they are ready to make their move and retake the city they built. Somehow I've got to insert the PC's in this mess, and was thinking of having the Azer getting lots of metal from the campaign world, in fact having them enlist and empower a faction of dwarves to split off, conquer a land ruled by Fire Giants and steal their iron mines to help the war effort. Presumably getting it from the Plane of Earth would be too easily discovered by the legions of spies working for the Sultan.

I'm having a bit of trouble nailing down what I want the City of Brass to be like. I would assume several thousand efreeti at least live there, and hundreds of thousands of slaves and visitors from the planes to boot. Maybe I'm off by an order of magnitude. Or two. Does anyone know of any published stuff regarding the City of Brass I can use to help me flesh out the place? Any ideas would be welcomed, thanks!