Siren & Scion (Mages of the Wheel, Band 3)

She was beautiful the way the ocean was beautiful. In a new way every time one looked.
She is water, bright and alluring, fathomless and profound. He is a bridge between peoples, artist and criminal, vengeful and compassionate.
Amara Mutar has risen to the highest ranks of Tamar society by her wits and ambition. But it is not high enough to keep those she loves, and herself, safe from a past that will not release her.
Cassian Haydar has sunk as low as it is possible to sink, but he intends to take back what is his, and crush those who took everything that mattered from him-after he's done stealing back all the other lives they've robbed.
In exchange for a betrothal that would secure Amara's position and freedom, the Tamaran Sultana sends her on a dangerous hunt for lost mages of the Third House, in the last place any mage should be. Amara and Cassian, brought together deep inside the Republic, discover they have nothing, and everything, in common.
But their paths were never meant to converge, and there are horrors in the heart of a rising Empire that threaten both Amara's plans and every mage in Tamar. Knowing the fate of the Circle rests in her hands, Amara must choose whether to serve her heart, or her people.
He was a shore upon which she crawled from the dark deep of her magic and fell against to breathe, and taste the air again.