Invincible by Beth D. Carter

Lee Masterson is a gun for hire. He’s shut himself off to almost everything, existing with the memory of a woman he loved fiercely but had to let go for her safety. But his carefully constructed walls are shattered when a threat is made against Lidah Wilcox’s life, sending him back to Kentucky in a desperate effort to protect her.
The hole in Lidah’s heart never fully closed when Lee died, and when he suddenly resurrects from the grave, she’s overwhelmed with emotion and memories. Twenty-two years of emptiness lie between them, and she’s unprepared for the love that comes surging back to life.
Lee will do anything to protect Lidah, yet he can’t walk away for a second time. Danger brought them back together, but can they keep each other safe when it’s stalking them?