The Camelot Betrayal (Camelot Rising #2) by Kiersten White

EVERYTHING IS AS IT SHOULD BE IN CAMELOT: King Arthur is expanding his kingdomโ€™s influence with Queen Guinevere at his side. Yet every night, dreams of darkness and unknowable power plague her. Guinevere might have accepted her role, but she still cannot find a place for herself in all of it. The closer she gets to Brangien, pining for her lost love Isolde, Lancelot, fighting to prove her worth as Queenโ€™s knight, and Arthur, everything to everyone and thus never quite enough for Guinevereโ€“the more she realizes how empty she is. She has no sense of who she truly was before she was Guinevere. The more she tries to claim herself as queen, the more she wonders if Mordred was right: she doesnโ€™t belong. She never will. When a rescue goes awry and results in the death of something precious, a devastated Guinevere returns to Camelot to find the greatest threat yet has arrived. Not in the form of the Dark Queen or an invading army, but in the form of the real Guinevereโ€™s younger sister. Is her deception at an end? And who is she really deceivingโ€“Camelot, or herself?