Unhinged Cain

Kirby wished for a new life, but the Devil sent her Cain.
I knew what my calling in life was at a young age. I was the embodiment of death. The scent of blood and watching the life fade from something's eyes was more delicious than any dessert. With my twin Abel by my side, we reveled in the pain of others and the knowledge that we were above it all. Not even the FBI could hunt us down.
The one thing I hadn't accounted for was Kirby and the unusual spark of emotion she created. Being a psychopath, I knew my range of emotions had always been limited. Things like love, regret, and empathy eluded me. Yet I couldn't stop stalking the woman that had piqued my interest.
But all decisions had consequences, and hunting Kirby wouldn't just test my own rules. It would pull on the one bond I had, and Kirby was the hammer that might cause mine to splinter.
To the outside world, I had a life that most would say was privileged, but to me, it felt like the walls were caving in and trying to crush me with their rules of conformity. Little did I know that my life was about to change forever. One drive was all it took. One decision to turn down a wrong road, led to one heated glance that would catch the interest of the most notorious serial killer the FBI had ever chased.
Once I was in his grasp, my world turned on its axis, leaving me breathless and desiring things I could never have imagined. My mind became a war ground between my conscious and my growing passion for a man my heart should never want.
Would I be able to love him regardless of what he was, or would I end up on the wrong end of his blade?