A massive walled city surrounded by an impassable desert (that nonetheless draws in new people; they just can't leave). The native species is fae but also there are large human populations which include both newcomers and people who have been living in Askalde for generations.
Fae can command humans such that the humans experience psychic overload if they don't obey the fae's orders. Humans can enter a fae's service so that only that one fae can command them, or they can stay in the human quarters where fae cannot legally be.