Kriess is an ex-"sweeper", a member of an elite CIA task force trained to track down and bring in rogue agents. To be a sweeper means to be expertly trained in the art of hunting and killing, and Kriess was not only a sweeper himself, but the agent in charge of training and leading the entire program. Only something went wrong - an assignment to track down an agent involved in a Chinese espionage plot ended in a bloody massacre, and threatened to reveal a monumental government cover-up. Kriess was quie