Forty years ago, Bob Lee Swagger's father, a state trooper, was killed by two robbers in an Arkansas shoot-out. Now a young writer has arrived at Swagger's door with some penetrating and troubling questions. What really happened that long-ago Arkansas night? The powers that be don't want that question answered, but Swagger, to his surprise, finds that he does -- even if it means having to use his long-abandoned combat skills and cunning to find out. Like the infrared "black light" that exposes a sniper's target in the night, Swagger homes in on the shadowy figures desperate to keep the secret of his father's murder buried.