As the Commander of the "Knights of the Vatican," a secret elite unit of the Catholic Church, it is Kimball Hayden's duty to ensure the protection and security of its dignitaries. However, his own past seems to catch up with him - a spirit from forgotten times, stronger, faster, and more ruthless than any soldier he has faced before. This unknown assailant systematically decimates Hayden's former special unit, the Force Elite, but not without leaving small clues behind. For carved into the flesh of his former comrades is always one word: Iscariot. Now, it is up to Hayden to eliminate this nearly overpowering adversary before he can carry his personal vendetta into the very walls of the Vatican.