The Mountain's Call (Luna)

Tales are told of the mysterious, powerful Mountain where the gods--powerful beings in the form of white horses--live. But Valeria knows no woman has ever been called to the Mountain. Until she feels a strange pull and answers the call--as a boy...When her secret is discovered Valeria loses all that she's won. Her anger and frustration with the Empire might be enough to give the barbarians a way into the Mountain. And so the Empire now depends on the will, the strength and the loyalty of one Rider. A Rider who has been rejected by all but the gods...