Son's Betrayal (The Imperial Series) - Imperial, #5

As the youngest son of the powerful Emperor Damuk, Prince Rowan is expected to follow orders and stay out of trouble. Unfortunately for him, the adolescent prince can't seem to do either of these things with any real success. When he's not being lectured by his stern father, he's forced to endure the quiet disappointment of his sweet mother. His brother finds him irritating and his sisters can't stand the sight of him.
He has no friends and no ambition in life. In short, he just can't seem to find a place in his family or in the Empire, and he doesn't care to try. All Rowan really wants is power, the kind of power his father wields. So when a beautiful young courtier offers him just that, he has few reservations and even fewer questions. Seduced by her dark beauty, Rowan agrees to follow her, abandoning the Abital Empire against the express wishes of his father.
And that is only the beginning of his adventure...