Jacob the Enforcer belongs to one of the many Nightwalker races that thrive on the dark of night. He has a job to do for his species and it's rather straightforward. He polices his people. During the full moon their animal urge to mate overcomes them, and if they stay within their race they never need to encounter the Enforcer. But if they cross the line and turn their lust to another species...say humans...it's Jacob's duty to prevent them and then to punish them severely for it. As this 'madness' grows worse and worse for his people, there is hardly a family who hasn't felt the brutal sting of Jacob's justice. Punishment is so dire and so feared, Jacob can call very few others his friend and the life the Enforcer leads is a very solitary one.

Then one night during a hunt for one of his own, he encounters the first human woman who will tempt him in all of his 622 years of life. Isabella is a simple Bronx gal who works at her local library, lives with her sister and owns a cat.

She hardly expects a night of moongazing to change her life forever and send her falling for a man like Jacob in all kinds of outrageous ways. Heck, she certainly doesn't expect that he isn't exactly a 'man'... although he sure looks like one, smells like one and boy-oh-boy does he feel like one!

As for the Enforcer, Jacob finds himself tempted beyond reason, needing Isabella to the point that he begins to strain against every law he has always upheld.

But before long the couple finds themselves fighting for their lives against evil, Jacob's bretheren, and even their own desires for each other. How can they find the way to resist one another before Jacob faces his own punishments...or before Bella ends up dead, torn up from the animal passion inside of him that she, as a human, is too frail to ever endure?