The instructor

Former Marine trainer Derek Harrington, the hero of Hendricks's hard-driving debut and series launch, has been offered $50,000 by Marshal, the evangelical leader of Sanctuary, a mysterious religious group in the wilderness of Upstate New York, to teach its members the strategy of SERE (survival, evasion, resistance, and escape). Since retiring from the Marines, Derek's struggling bushcraft school has barely made enough to keep him alive, let alone pay for child support and his ailing father's care facility. After seeing how much weaponry Sanctuary has amassed at its backwoods compound, Derek touches base with the FBI, which agrees to use him as an undercover agent investigating domestic terrorism. Once on the job, Derek gains the grudging respect of his trainees, but as an outsider, he's never free from suspicion. As the brutal training progresses, Derek slips up one too many times, revealing his true purpose, and he has to scramble for his life. Hendricks, a former Army captain and intelligence officer, brings authenticity to this dip into the world of survivalist fringe culture, though readers should be prepared for a predictable plot and stock characters. Military action fans will find much to like. Agent: Irene Poelle, Irene Goodman Literary. (Apr.)