Heir of Iron by J.S. Bangs

Mandhi has spent years looking for her lost brother Navran. Their ailing father is near death, and Navran must inherit the title of Heir of Manjur, descendant of an ancient king and leader of a secret sect. More importantly, if Navran returns then Mandhi won’t have to marry to provide an heir, leaving her free to elope with her bodyguard.

But the Navran she finds is not the man she needs. He’s a drunkard and a gambler, and he has no interest in his religious duties. Mandhi attempts to reform him—but her efforts are interrupted when agents of the Emperor kidnap Navran. Mandhi must find out why the Emperor wants her brother, free him, and find a way to stay with her lover. And what she sets in motion will shake the foundations of the Empire.