Immortal Darkness — Stuart Jaffe

Nathan K -- he can hold two souls in his body. If he dies, he loses one yet lives on with the other. As long as he replenishes his second soul, he cannot be killed. Nathan K is immortal.

ABDUCTED

When Nathan and Robin are taken against their will, they end up under the thumb of a Colombian drug lord. In order to protect Robin, Nathan is forced to help defeat a rival organization. But his captors can never be trusted. Once they see how powerful Nathan is, they will never let him go. They'll want him forever.

And for an Immortal, forever truly means forever.

To survive, Nathan will have to draw upon all his power as an Immortal and use all his skills and training. Even if that means facing the only thing that truly terrifies him -- the Darkness. Anything to save Robin and survive being caught between two powerful and ruthless forces.

But that might not be enough.