In addition, for about three decades, Mr. Hunter has moonlighted as a novelist, well-known for entertaining fiction recounting the exploits of Vietnam War sniper Bob Lee Swagger and Bob Lee’s father, Pacific war veteran and Arkansas sheriff Earl Swagger. In the previous novel “Dead Zone,” readers learned that Bob Lee fathered a son with a Vietnamese woman. That son was adopted by parents who gave him the name Ray Cruz. He grew up to be a Marine Corps sniper, and in every sense fully his father’s son.