It's the law of the Pack - or anarchy.

For most of his life, Cade Warden has put the needs of his Pack first, setting aside everything else - even the emptiness he feels from having no mate. But Warren Pellini and his thugs have a biological weapon, threatening everything Cade holds dear.

Into his intensely focused, lonely life walks the woman he's been waiting for.

Packless for many years, Grace Pellini has edged back into the good graces of her evil brother, walking a dangerous line to gather information to aid the Nationally Allied Packs. Cade is everything she could have hoped for in a man and a mate, even if he can be pushy and overprotective.

In the midst of their rising passion and desperate search for the key to disabling the weapon, Pellini raises the stakes by calling an ancient Challenge.

Now its Grace's turn to put her protective instincts aside and stand by, Cade's life in her hands, as her mate risks everything for his people.