This book fits into the latest batch of women focused fiction where the main character is a young woman in distress who needs to find her path amongst a maze of options but typically with a deadline or else 'bad things' will happen. In this case the young woman is Miryo, a witch initiate who is about to undergo her right of passage to become a full fledged witch. She passes but in the process she discovers that all witches are born as twins with one twin being the witch and the other being sort of a souless being that needs to be desroyed. The trouble is that Miryo's twin was not destroyed and before Miryo can fully become a witch she must hunt down her twin and kill her. If she does not do this the magic within her, which she can't control until the twin is dead, will destroy her. To add to the difficulty, Miryo's twin has been living her life as a successful bounty hunter, adept at stealth and weapons and combat. So, the stage is set for what seems a pretty lopsided battle.

(Source: Warner Books)