A Secret Service agent is dead, an apparent suicide. A presidential candidate narrowly escapes an assassin's bullet. And Desk Three, a convert branch of the NSA, is searching for a chilling connection deep inside The Republic of Vietnam. Once, Charlie Dean was a Marine sniper in Quang Nam Province. Today he's a Deep Black operator, returning to Vietnam to find the source of some threatening e-mails. Instead, he comes face to face with a man he had...