A former soldier in the Marine Corps during Desert Storm (later changed to the War on Terror), Michael O'Bannon was chosen for the secret government task force Operation: Knightstrike. After many missions and deaths at his hands, Michael chose God over death and continued to serve as a chaplain.

After his duty was done, Michael became the father of St. Mark's Catholic Church in Boston. Living among the gangs and violence of the neighborhood, Michael takes the law into his own hands as Priest - a vigilante on a mission from God.