The Cain Deception. The Cain Series, #2

In this follow-up to The Cain Conspiracy, Matthew Cain finds himself on the wrong side of a hit man. After he is sent on an assassination mission in Russia, The Specter Project learns of a man seeking revenge for Cain's actions. After Cain hears of the man's intentions, he sets out on a frenetic search to find the killer before he makes good on his plans to kill both Cain and his girlfriend. Along the way, Cain finds more questions than answers about the mysterious assassin, who seems to be a ghost.
As Cain dives deeper into his quest, he starts to wonder about his role within the super secret agency and whether there are those above him who know more than what they appear.