The Priory of the Orange Tree by Samantha Shannon

Synopsis: Ead is a lady-in-waiting at the Inys court, where she is an outsider and is tasked with secretly protecting the queen. Arteloth is a Inys nobleman sent in exile to be an ambassador and spy in a land that has turned to the ways of worshiping Wyrms. TanΓ© is across the sea in Seiiki, where she is training to be a dragon rider when she gets caught up with a forbidden outsider. The doctor Niclays has been exiled from the West for trying to do the impossible. As the threat of the Nameless One, approaches, everyone must prepare for the coming conflict in their own way.