Submit to the Beast by April Andrews
When Tobias Thorn was abducted and taken to a strange, underground city, he had no idea how drastically his life was going to change. Now, back above ground he knows that something is different, that he is different, and that his craving for the man known as the Beast, is never going to go away.
Just as the Beast predicted, Tobias has no choice but to return.
But by returning, Tobias has no idea exactly what is going to be expected of him, or that he is going to have to make a choice, between the man he once was, and the man he is going to have to become.
In the end, Tobias may have no option but submit to the Beast.