A betrayal in winter

As a boy, Otah Machi was exiled from his family, Machi's ruling house. Decades later, he has witnessed and been part of world-changing events. Yet he has never returned to Machi. Now his father--the Khai, or ruler, of Machi--is dying and his eldest brother Biitrah has been assassinated, Otah realizes that he must return to Machi, for reasons not even he understands--even though he stands accused of his brother's murder.