Callous by Sybil Bartel

Bodyguard.
Tracker.
Silent observer.

Life was in the details. The weight of a government issued rifle, the trajectory of a bullet, the speed of the wind—those details were crucial in the Marines. But outside the military, that level of observation was currency, and I was selling my skills to the best security firm in south Florida.
Except I wasn’t on a job when I noticed the nervous brunette pushing through the crowd. Her hair loose, her shirt borrowed, she stumbled in too-big shoes before looking over her shoulder. I didn’t follow her glance. I didn’t have to. I’d already spotted the muscle after her. The question was if I was going to do anything about it. Before I could decide, her pursuer took aim. It was the wrong move.

Now everyone was going to find out how callous a bodyguard could be.