The Ashfire King — Chelsea Abdullah

A merchant and a prince trapped in the crumbling realm of jinn must figure out how to save one world to return to their own in The Ashfire King, the second book in the Sandsea Trilogy, perfect for fans of The City of Brass and The Bone Shard Daughter.
 
Neither here nor there, but long ago…

After fleeing a patricidal prince, legendary merchant Loulie al-Nazari and banished prince Mazen bin Malik find themselves in the realm of jinn. But instead of sanctuary, they find a world on the cusp of collapse.
 
The jinn cities, long sheltered beneath the Sandsea by the magic of its kings, are sinking. Amid the turmoil, political alliances are forming, and rebellion is on the rise. When Loulie assists a dissenter -- one of her bodyguard's old comrades -- she puts herself in the center of a centuries-old war.
 
Trapped in a world that isn't her own and wielding magic that belongs to a fallen king, Loulie must decide: Will she carry on someone else's legacy or carve out her own?

The Sandsea Trilogy
The Stardust Thief
The Ashfire King