Book 1 in the After The Exit series.
"As top energy executives across the world begin dropping dead, Viper comes out of retirement to do what she does best: the impossible. But nothing is ever as easy as it seems, especially when the target is her husband. Racing across war-torn Ukraine, two operatives must forget the past and focus on finding the one man who can help locate a deadly foe before it’s too late… and Viper ends up dead for good."