Kill Shot (The Collective #1)
Liliana Hart

Gabe Brennan holds the weight of the world on his shoulders. As one of the most brilliant black ops agents the CIA has ever employed, he knows it's no one's fault but his own that his child was gunned down in cold blood. He might not have been able to save his daughter, but he's determined to save his wife. He only has to find her first.
Sexual tension crackles between Gabe and Grace from the moment they're reunited, but between the man who is hunting them, a secret that's been buried for eighty years, and a turbulent past--the odds are stacked against them.