Half-demon, half-human, Lillith is bound by a bargain with the devil and forbidden to feel pleasure. She draws upon her dark powers and serpentine grace to lead men into temptation. That is, until she faces her greatest temptation, Heaven's own Sir Hugh Castleford. Once a knight and now a Guardian, Hugh's purpose has always been to thwart Lillith, even as he battles treacherous hunger for her. When a deadly alliance unleashes a threat to humans and Guardians angel and demon are forced to fight together against evil and against a passionate desire for each other.