Chalice

Chalice by McKinley, Robin. mass_market edition. ISBN: 9780441018741.

The earthlines speak to Mirasol, but her family has lived in the demesne for centuries, and many of the old families can hear the land. She knows that the violent deaths of the last Master and Chalice have thrown Willowlands into turmoil; but she is only a beekeeper, and the problems of the Circle that govern Willowlands have nothing to do with her—although she wonders what will become of her demesne, because the Master and Chalice left no heirs to carry on their crucial duties. And then the Circle come to Mirasol, to tell her that she has been chosen to be the new Chalice; and the Master she must learn to work with is a Priest of Fire, a man no longer quite human, whose touch can burn human flesh to the bone.