The Iscariot Agenda (Revised Edition) - The Vatican Knights, #3

Kimball Hayden is the Commander of an elite commando group known as the Vatican Knights, a black-op force that works for the Church to protect its sovereignty, its interests, and the welfare of its citizenry. But Kimball is being stalked by someone from the past, a soldier that is stronger, faster, and far more brutal-an assassin so deadly not even the Vatican Knights can stop him. This Alpha Assassin has set Kimball within the crosshairs and is systematically destroying his old team of elite fighters, the Force Elite.
Kimball is then sent to confront this killer who leaves behind lettered clues carved into the flesh of his teammates: ISCARIOT. Not only does Kimball have to battle something far more dangerous than anything he has ever encountered, but he must destroy this Alpha Assassin before this killer brings his personal war to the Vatican.