The words of kings and prophets by Shauna Lawless

Ireland, 1000 AD. Gormflaith is unhappily married to Brian Boru, High King of Ireland, and although a queen she struggles with her limited position. As an immortal Fomorian with the secret gift of magic, Gormflaith has a burning desire: to find and destroy the hidden fortress of her sworn enemies, the Descendants, who seek to kill her kind at all costs. She begins to use her magical powers, and discovers she is more skilled than she ever realised – but can she control what she will become? Meanwhile F?dla, the Descendants’ healer, mourns her banished sister but clings to life as the guardian of her young nephew. She seeks a place of safety for them both, but he has secrets of his own that could threaten everything – and F?dla must do all in her power to keep him hidden away from those who would use him for evil.