Crow and Firefly

The laws of man and nature are harsh and decisive: Unwed mothers are not allowed to raise their children, and shapehifters must wed and consummate the marriage to satisfy the magic that would otherwise render them beasts forever upon the morning of their twenty-third birthday. With the life of his sister and newborn nephew at stake, shapeshifter Ari is trapped in a castle and compelled to accept a situation he'd dreaded: he is forced to marry Lord Dagur, a man he's never met. A man called "The Cruel." A man he fears, and not just because he fancies someone else.

Dagur, the king's nephew, is attacked on his way to court. Ari must figure out who the enemy is and who would want the king dead.