Poison Study – Maria V Snyder

The story follows Yelena, a young woman locked in a dungeon and sentenced to death for murdering her abuser. On the eve of her execution, she is offered an extraordinary reprieve: become the personal food taster for the Commander of Ixia. 

While she gets to live in the palace, she faces constant threat of assassination from political factions. To ensure her absolute loyalty, the chief of security deliberately poisons her with a substance called Butterfly’s Dust, requiring her to receive a daily antidote to survive. As rebels plot to overthrow the government, Yelena begins to develop magical powers she cannot control, forcing her to unravel her mysterious past to survive