Shadowheart - Shadowmarch Book 4

Barrick Eddon, prince of Southmarch, is no longer entirely human. He has vowed to safeguard the legacy of the dark Qar race, and must now decide where his loyalties lie. His twin sister Briony has a difficult choice of her own. Her father, King Olin, is held captive by the Autarch, a mad god-king who plans to use Olin's blood to gain unlimited power. And the castle of Southmarch still remains in the possession of Hendon Tolly, Briony's murderous relative.
As time runs out, will Briony decide to save her father's kingdom .