Kiss Me While I Sleep by Linda Howard
It's a job that makes a killing. Efficient, professional and without apology, Lily Mansfield is a hired assassin, working as a contract agent for the CIA. Her targets are the powerful and corrupt, those who can't be touched by the law.Now, after 18 years of service, Lily has been drawn into a dangerous game that hasn't been sanctioned, seeking vengeance for her own reasons. Lily knows that she can be taken out in an instant. And if it's her time, so be it. She intends to go down fighting. Lucas Swain, a CIA agent himself, has orders to either bring her in or bring her down. Yet he too is drawn into the game with Lily, dancing on a tightrope as they battle a tenacious foe who is dogging their every step.