Epic Fantasy Paranormal Romance.
The magicians of the empire are no longer able to have children and no one can provide a reason or cure.
Halidan tor Ephram is human, a mortal in a land where the very air she breathes is controlled by the Elemental magic of her Elvish overlords. The lowest caste in the Empire, she has no recourse under the law, no protection other than the good will of Elves she and her learned father serve as tutor. When her father dies, that protection disappears in an instant, leaving her with nothing but her education and her pride to depend upon.
Eioth is the High Lord of the North West Demesne, a Master of the Elemental Magic that regulates everything in the Empire, from the weather to the harvest to healing the sick and injured. Air, Earth, Fire, Water, he can bend all of them to his Will in the service of his people. He can solve any of their problems, except the empty cradles gathering dust in the nurseries of the High Elves.
Love of books brings them together. One ancient book, on the uses and techniques of sex magic, dismissed by scholars and long forgotten, threatens to tear them -- and the rest of their world -- apart.