IN this tough, gripping read, C. J. Box overlays the noir western style of his Joe Pickett Wyoming game-ranger thrillers, and their atmospheric volatility, with something of the concrete police procedural. Detective Cody Hoyt, a Lewis and Clark County sheriff's department investigator, chain smoker and alcoholic struggling with two months' sobriety, is on the trail of whoever murdered his AA sponsor and left his remains in a burned-out cabin in the Big Belt Mountains. His investigations link the dead man to a group running a wilderness adventure in Yellowstone Park. Coincidentally, his estranged son has signed up for the same trip. As the chase unfolds, Box adds some classic Agatha Christie-style intrigue into what he calls his "witches' brew of Old West and New West".