The intensity with which Department of Natural Resources Conservation Officer Grady Service pursues his job makes this first entry in Heywood's (The Snowfly) new series a standout. The book shares some traits with an urban police procedural, but the milieu—Michigan's Upper Peninsula—and focus on the environment differentiate this investigation. A 47-year-old native of the region and divorced Vietnam vet, Service is fiercely independent and passionate about the land. The section of the U.P. that Service cares most about is the Mosquito Wilderness Tract. That's where he was, patrolling along the river, when he encountered an odd, wary older man with a camera, a hammer and a notebook. Soon that very spot is the site of two suspicious fires, after which a local poacher is found shot dead in the back. County detectives look into the murder, but Service can't shake his suspicion that the tract is facing some sort of threat. When a handful of rocks he picks out of the ashes turn out to contain diamonds, Service must race against time to find out what's really behind the murder and arson. Under Michigan's pro-development governor, just a whisper that diamonds may lie in the bedrock could threaten the pristine wilderness area. A strong sense of place, a protagonist with a moral commitment to his job and a fleshed-out community of hard-working conservation officers and their colleagues in law enforcement make this a promising beginning to the series. (July)