R.A. Fisher 
The Kalis Experiments [EPUB ebook] 

Syrina is a Kalis: a master of disguise, assassin, and spy. Her kind has served the High Merchants’ Syndicate for a thousand generations.
She receives a surprising gift from her master, and she realizes something isn’t right. The High Merchants don’t do anything without a reason. 
When things don’t add up in an otherwise normal investigation,  she follows the trail to the steam-powered city of Fom. There, she learns of a machine that could end civilization a second time. 
Will Syrina stave off disaster, or seek revenge?