The Undying King — Grace Draven

The stories are told in whispers, even after so long: of a man whose fair rule soured when he attained eternal youth. Imprisoned by a sorceress wife in a city out of time and place, he has passed into legend. Few believe in him, and fewer would set their hopes on his mercy. But Imogen has no choice. To break the curse that's isolated her since birth, she'll find the Undying King--and answer his secrets with her own...