It began with a single, terrifying act of violence. Tyler Vance, widowed father of a four-year-old, pulled his truck into a bank parking lot in North Carolina. An armed robber exited the bank, pointed his gun at Vance, and ordered him out of the truck. It was a supreme moment of life and death. And Vance responded the only way he knew how--as a trained killer, whose deadly precision served him 20 years ago as a special operative. In a blinding flash...