Lynn Flewelling: The Bone Doll's Twin

For three centuries a divine prophecy and a line of warrior queens protected Skala. But the people grew complacent and Erius, a usurper king, claimed his young half sister's throne. Now plague and drought stalk the land, war with Skala's ancient rival Plenimar drains the country's lifeblood, and to be born female into the royal line has become a death sentence as the king fights to ensure the succession of his only heir, a son. For King Erius the greatest threat comes from his own line - and from Illior's faithful, who spread the Oracle's words to a doubting populace.

As noblewomen young and old perish mysteriously, the king's nephew - his sister's only child - grows toward manhood. But unbeknownst to the king or the boy, strange, haunted Tobin is the princess's daugther, given male form by a dark magic to protect her until she can claim her rightful destiny. Only Tobin's noble father, two wizards of Illior, and an outlawed forest witch know the truth. Only they can protect young Tobin from a king's wrath, a mother's madness, and the terrifying rage of her brother's demon spirit, determined to avenge his brutal murder.