Maine's backcountry is being invaded by feral hogs. Hordes of drunken, half-naked college students are partying up and down the winding Saco River. A teenager who disappeared years ago is about to be declared dead. And a retired state trooper remains irrationally obsessed with her case.

All of the above may or may not be connected to a muscle-bound rich kid who preys on women, the half-buried remains of a baby girl, two mysterious women in red wigs and a rural slumlord whose shacks have an unfortunate habit of exploding in flames.

"Knife Creek," Paul Doiron's eighth crime novel featuring Maine game warden Mike Bowditch, begins innocently enough when the hero is assigned to shoot the invasive hogs. But when his hunt turns up the hog-chewed remains of the baby girl, all hell breaks loose.

As always with a Doiron novel, the characters are so well-drawn you can almost reach out and shake their hands, and the rural landscape is so vividly portrayed that the reader can smell wildflowers, marvel at the swarms of fireflies and feel the sting of the blood-thirsty insects. But the author's finest achievement is the evolution of Mike Bowditch himself.

Doiron's hero has come a long way since "The Poacher's Son," when he was introduced as a hot-headed, insubordinate rookie game warden struggling to keep his personal demons in check. As the series has progressed, Bowditch has gradually matured, coming to terms with his troubled past, finding love and finally earning the respect of supervisors who once longed to be rid of him.

"To spend as much time in nature as I did was to be confronted constantly with mysteries," he reflects toward end of the new novel. "The natural world had so humbled me that it had reawakened some of the eagerness I had felt as a boy to believe in a universe of greater meaning."