To Play the Devil. Available on Amazon.

Here's a sneak peak. I figure if I can't hook you on the first paragraph then that's not good. 

So many labs destroyed, so many innocent people murdered; all for a false sense 
of justice. At some point she began to kill just for the simplicity of killing. Hammering 
away at the metal memories of restless nights filled her mind. So many of those nights 
led to her using alcohol to numb a pain that could never truly heal. Shaking her head 
Anna began to focus on her work for a few seconds more.