When the mutilated body of a black man is found hanging from a tree in Mackinac County 275 miles away across the wild Upper Peninsula of Michigan, Porcupine County Sheriff Steve Martinez is dismayed. His bailiwick is ninety-nine per cent white, and the victim, an army veteran, had just been acquitted by an all-white jury in the rape of a white woman. Steve had feared racial repercussions after the verdict and suspects bigotry led to the violent death of Billy Gibbs. But a mystery surrounds the victim himself. How could an ordinary truck mechanic possess such a large bankroll? Why was he so concerned about the well-being of his brand-new, tricked-out pickup truck? Steve is severely shorthanded, but to shine light on Gibbs and to find his killer-or killers-Steve and Sheriff Selena Novikovich, his counterpart in Mackinac County, dig deep into the case. With the help of their deputies, several state troopers, a retired FBI agent who must fend off a hostile CIA, and a military police colonel willing to put his career on the line for the comrade who saved his life in Iraq, the two sheriffs doggedly track the clues across five states. The cops turn up another murder as well as a clutch of fervent neo-Nazis, one of whom is a gorgeous but vicious woman whose sexual proclivities rival those in Fifty Shades of Grey. The Riddle of Billy Gibbs, the sixth in Henry Kisor's Steve Martinez series, vividly explores a troubling side of American life.