Shadow Assassin by Elle James

After completing a difficult and secret task to eliminate the leader of a Russian terrorist organization, former Navy SEAL and expert sniper, Dane “Striker” Ryan, is booted from his SEAL team, destroying his reputation as a trusted servant to his country. Burned, angry and out of work, he agrees to take an assignment from a shadowy organization recruiting this Navy SEAL for a special project. For a sizable sum of money, he is to eliminate a dangerous assassin by any means necessary. Unemployed, and with no means to make his next rent payment, he accepts the lucrative work.

Alex Sokolov, self-trained assassin, is on a mission of revenge for her parents’ deaths, a mission that has spanned a decade. As she nears her ultimate target, the hunter becomes the hunted.

Tasked to kill each other, Striker and Alex join forces in this international intrigue to discover the kingpin orchestrating the murders of secret agents, including Alex’s own parents.