'Geography is destiny," Leonard Shuler (Noah Wyle) says in a voice-over at the start of the somber Appalachian tragedy The World Made Straight. As he speaks, the camera takes us across an overgrown piece of mountain in Madison County, N.C., cut along one side by a two-lane road, the other by a dirt-colored river.

For Midwesterners, that means wide spaces; open vistas; possibility, says Leonard. For his neighbors, who live their lives in the overgrown fields, muddy streams, and rough back roads of Appalachia, the world is limited, stifling.

Adapted from the acclaimed 2006 novel by poet Ron Rash, The World Made Straight is a coming-of-age story about a teen desperate to escape his roots, and the middle-age former teacher who helps him find a direction.

British actor Jeremy Irvine (War Horse, The Railway Man) plays Travis Shelton, a 17-year-old dropout already poisoned by the despairing, bleak view long beaten into him by his father.

Kicked out of his house, Travis takes refuge at Leonard's trailer home. A prodigy who taught history at a school in the North, Leonard returned South in disgrace when he ran afoul of the authorities. Now, he makes a living selling pot - though he never seems to use it himself.

His place is shabby on the outside. Inside, it's a treasure trove of books, including a series of journals kept by Leonard's great-great-grandfather during the Civil War. Travis feels, for the first time, as if he belongs.

Weighed down by his own failures, Leonard "lives in a passive voice," as he puts it. But he comes alive when he sees Travis' potential. He helps the boy study for his GEDs, and imagine a life beyond Madison County.

The older man also teaches the boy about the importance of his roots. He explains the bloody, tangled history of the war in Madison County. Taking him to a famous battle site, Leonard tells Travis how members of the same family fought on different sides. And in one infamous incident, a homegrown company of soldiers massacres an entire family, including a 12-year-old boy.

Not everything is wine and roses for Travis and Leonard. They cross local drug lord Carlton (Steve Earle), a vicious sociopath whose ravages provide the story with its momentum. The brief eruption of violence that ends the story will strike some as contrived, as will a subplot about Carlton's plan to turn Leonard's lover (the glorious Minka Kelly) into a sex slave.

But The World Made Straight transcends its own limitations. Shot with a rigorous, poetic simplicity, it paints a complex, sophisticated picture of human social life and the moral obligations that come with it.

The film illustrates how the most powerful and welcome stabilizing forces in human life - history, family, geography - can turn so easily into deadly traps.

The World Made Straight *** (out of four stars)

Directed by David Burris. With Noah Wyle, Jeremy Irvine, Adelaide Clemens, Minka Kelly, Steve Earle. Distributed by Millennium Entertainment.

Running time: 1 hour, 59 mins.

Parent's guide: R (violence, drug use, sexual violence, profanity). 

Playing at: PFS Theater at the Roxy.