Zara the Wolf

Mountain warriors raid Zara's village and make her a slave. That should have been her destiny, but Zara resists to the amusement of her captives, who let their young warriors train on her, assuming they would cripple or kill her eventually. But she survives the training and escapes—a savage warrior in a civilized land ruled by royalty.
Zara tries to avoid the nobility and their unrealistic "requests" to help wipe out the mountain tribes only to come to the attention of a duke and asked to save the daughter of a baron, who was captured in a recent raid. She succeeds in freeing the girl only to be given an assignment to investigate a group called Sirens—individuals capable of twisting the mind with illusions—who are intent on replacing the nobility.
Thus begins a perilous journey with the baron's daughter as her cover for visiting the dukedoms. A journey that brings the young baroness and Zara close as they fight to survive savages, Sirens, and royalty.