Starcrossed, tome 3
Josephine Angelini2012

She must rise, or they will fall ...Helen's powers are increasing--and so is the distance between her and her mortal friends. To make matters worse, the Oracle reveals that a dangerous traitor is lurking among them, and all fingers point to Orion. Still unsure whether she loves him or Lucas, Helen is forced to make a terrifying decision, or risk all-out war. The final book in this heart-stopping trilogy.

Titre original : Stracrossed, book 3: Goddess (2012)