The Fourth and final book of The Dragon Jousters. ML is a really good writer, and I like alot of her books. She has written over 50 books.
Kiron has secretly gathered an army of dragon riders to seek refuge in the abandoned desert city they have named Sanctuary, where they join with other dragon riders to rid their world of both war and magical domination. But now it is time to build a new society in Aerie: an ancient city that seems to have been designed for dragon riders and their dragons.