Much as in “Reservation Road,” “In the Bedroom,” and a handful of other recent revenge yarns, there comes a point in “Red” when the line separating righteousness and retribution evaporates in a fog of fear. Here is a tale of arrogance run amok, yes, but also of the way that anguish can be channeled into unhealthy endeavors, where in a fit of greed and grief, three intersecting lives succeed in unleashing a campaign of mutually assured destruction.

“Red,” which was adapted by directors Trygve Allister Diesen and Lucky McKee from the novel by Jack Ketchum, is also a case study in how the concept of shame is seeping out of our society, and in how seeking to balance the scales of justice can still lead a man astray. Avery Allan Ludlow, played by the great Brian Cox, is an even-tempered (or is it no-tempered?) man of quiet but hard-won convictions. Ludlow, a widower and veteran of the Korean war who runs the local hardware store, is a man of deceptively simple ambitions, waking every morning to feed his dog, Red, before setting out to fish along the banks of a nearby river. On the morning we wake with him, Ludlow encounters three teenagers coming up the path, shotgun in tow, foolishly trying to hunt deer while neglecting the skill or the foresight to camouflage their odor. In a flash of senseless violence, the dog is dead and Ludlow is alone.

Ludlow takes up the horror of Red’s murder with the boy’s father, Michael (Tom Sizemore), who clearly doesn’t appreciate the accusation against his son. The he turns to the law, but is distraught to discover the limited punishment that accompanies the slaying of an animal. Finding no satisfaction in the law, Ludlow revisits the boy’s family in an effort to confront the killer, Danny (Noel Fisher). When a local TV news reporter sniffs outs the story and interviews Ludlow, the result is vandalism and a campaign of intimidation. But as Danny continues to deny his involvement, even to Ludlow’s face, a brutal cycle of tit-for-tat action ensues. Danny lacks a conscience, and Ludlow has lost his sense of when enough is enough.

If that sounds tedious and violent, Mr. Cox continually keeps things interesting. Ludlow, who has witnessed the worst kind of fear and bloodshed firsthand, considers it a matter of principle that the perpetrators of this crime should at least be confronted about what they have done. Even as Michael struts about town, telling Ludlow how things are going to be, our protagonist keeps his voice cool and mannered, seemingly aware of the difference between a war and a conflict.

But when Ludlow finally snaps, sinking to Danny’s level to teach him a lesson, his shift from wise old man to violent nemesis is startling. As repeated house visits lead to round-the-clock surveillance, the fisherman begins to see that these children are lashing out at their own demons. Michael is clearly a man who diffuses his pent-up rage by unleashing it on his boys. Danny has channeled that anger at his father into violent outbursts.

For his part, Ludlow’s nightly spying missions began as a way to learn more about others, but soon they become instructive about him; his own flaws and obsessive-compulsive tendencies float to the surface. He believes he is unequivocally in the right, but as his self-righteous urges lead him to clash with this strange family, he becomes an instrument of vengeance rather than a voice of reason — a critical turning point in any battle, large or small. In a brave and subtle shift, Messrs. Diesen and McKee start to turn on their hero. “Red” isn’t a tragedy or a thriller, but an existential study in what becomes unavoidable doom.

Danny and Ludlow are like phosphorus and chlorine, two essential elements that explode when mixed, and while the movie is initially about people trying to talk things out, it increasingly seems as though Danny was determined to do something bad, and chose the one man who wouldn’t let it go. Sure, Ludlow technically has morality on his side through most of the story. But “Red” suggests that knowing when to walk away — which shouldn’t be confused with surrender — is more important than convincing someone at any cost that you are right.

ssnyder@nysun.com