Edgar-winner Box's superior thriller carries some characters and themes over from his two-previous stand-alone, The Highway and Back of Beyond, as investigator Cassie Dewell relocates to North Dakota's boomtown oil fields. In the subzero prairie, the little town of Grimstad is bursting with thousands of roughnecks, its infrastructure and law enforcement sytem are almost over-whelmed, and ruthless drug dealers are flocking to a wide-open new frontier. Cassie arrives just as a series of brutal murders signals a war between drug gangs - although the missing duffle bag the criminals are searching for has accidentally wound up in the hands of a special-needs paperboy, 12-year-old Kyle Westergaard. Kyle just wants a stable home life, but his possession of the bag full of drugs and money sets off more violent deaths. The story's brisk action is broken into alternating sections as Cassie and Kyle try to figure out what's going on and what they must do. The vulnerable boy's plight gives emotional heft to the criminal investigation, balancing cynicism with warm empathy.