Island of Darkness — Richard S. Tuttle

Just as peace between Omunga and Sakova appears to be a certainty, an evil mage steals the body of the newly chosen Katana, leader of the Omungan people. As the new Katana plots the destruction of the Sakova, a strange mystical disease ravages the country producing widespread famine. Both countries stand poised to annihilate each other, but the Star of Sakova fears a greater threat, which is brewing unseen across the ocean. To confront that new threat, she must preserve the armies of her Omungan enemy. Against all odds, she embarks upon a path towards a peaceful solution to the war, a path that could likely imperil the very existence of her own people. Meanwhile, two young orphans discover that they are sisters and set out from the Sakova on an ocean voyage to discovery their roots. What they discover is enough to terrorize both the Omungans and the Sakovans, if the young sisters manage to escape the Island of Darkness to tell their story.