Queen of Spades by Jillian West

Annika Knowles knows better than to get involved with powerful men. She nearly became collateral damage in a war once before, but she ran, making a new life for herself in the seedy underbelly of Las Vegas.

The High Roller Club offers someone with her skill set the chance to make her own way, and she’s mostly managed to keep her head down. Well, if you don’t count how she keeps falling into bed with one of the club’s security specialists. Or how she accidentally caught the eye of one of the most dangerous men in Vegas. And we won’t even get started on the way his ruthless enforcer watches her every time she enters a room…
Actually, she’s terrible at lying low.
But all of these problems are easily managed.
What isn’t? Severing the ties to her old life.
Can Annika’s new allies keep her safe? Or will she have to cut and run again, losing everything she’s built for herself in the process?