A lean, unsparing carousel of vigilante-style comeuppances, "Blue Ruin" is a meat-and-potatoes thriller filled with gristle but not an ounce of fat. Jeremy Saulnier (who previously directed 2007's acclaimed, underseen Halloween-set horror-comedy "Murder Party") is at the brutally confident helm, bringing newfound immediacy and quaking apprehension to a plot that, on paper, sounds as if it has been seen many times before. Joel and Ethan Coen's past crime oeuvre—most notably, 1984's "Blood Simple," 1996's "Fargo," and 2007's "No Country for Old Men"—appear to be definite inspiration, but Saulnier's tribute remains just that, going off in its own direction once the connection has been made. Choosing to provide a reeled-back, tautly spun amount of exposition while leaving it to the audience to fill in the gaps as necessary, he treats his viewers with a level of trust and respect not often seen in bigger studio filmmaking.

Eaten up by an awful tragedy from his past, thirty-something beach bum Dwight (Macon Blair) now all but lives entirely off the grid, scrounging for food in boardwalk trash bins and regularly sneaking into unoccupied homes to bathe himself. When he learns that Carl Cleland (Brent Werzner)—the man believed to have killed his parents—is about to be released from prison, he hops in his old, rusted blue Pontiac Bonneville and heads for Virginia with vengeance on his mind. Promptly dispatching of Carl in a bar restroom, Dwight goes on the run. Making a pit-stop to inform estranged sister Sam (Amy Hargreaves) of what he's done, it becomes readily apparent that the dead convict's outraged backwoods family are hot on his trail, not about to stop their pursuit until he is dead.

The first act of "Blue Ruin" concludes where most revenge flicks end their third, with Dwight methodically stalking the newly free Carl and promptly dispatching of him in one swift, blood-spewing stab to the temple. With over an hour left to go, writer-director Jeremy Saulnier rivetingly follows his protagonist in the aftermath of committing a deed of eye-for-an-eye retribution. Getting rid of the man who was locked up for killing Dwight's mom and dad twenty years earlier is far from the end of his ordeal as new details come to light about the circumstances behind the double homicide. Moreover, Carl has plenty of folk on his side not about to walk quietly into the night. An intense, deliberately coiled cat-and-mouse game follows, playing out against the hardscrabble backdrop of winding mountain roads, desolate fields and lonesome single-family homes among the rural American underbrush. None of it, per se, breaks new ground—the story's trajectory is a straightforward one—but Saulnier knows that a movie's success is determined not by what it is about, but in the astuteness of its handling and delivery.

A relatively unknown actor prior to the release of "Blue Ruin," Macon Blair should find himself receiving some much-deserved notoriety with his exceptionally intuitive, deftly powerful performance as Dwight. He is at the center of every scene and very nearly every frame, building from the ground up a stingingly raw, vulnerable portrait of debilitating loss and sacrificial strength. That Blair is not immediately recognizable is to his further benefit; watching him, he ceases to be anybody other than the character into which he disappears. Making inerasable marks with only a few scenes each, Devin Ratray (2013's "Nebraska"), as childhood friend Ben, and Amy Hargreaves (2011's "Shame"), as sister Sam, seem to have created full-bodied portraits within Saulnier's urgently observant gaze. When Sam learns what Dwight has done, the quiver in her voice serves as an exclamation point to her reaction, happy that Carl is dead but angered that her brother's actions have now made them both—and Sam's two young children—potential targets.

Dwight is unskilled when it comes to weapons and it is not normally in his nature to commit violence with them, but he is cunning. If he allows his rancorous emotions to get the best of him, he has also prepared himself for the consequences, no matter how grim they may be. "Blue Ruin" watches him with a shrewd knowledge of building suspense through audience discomfort, onscreen silence, and the resulting anxiety of what is to come next. Without giving the finale away, the film culminates exactly as it should, and must. A gross injustice was not merely done to Dwight and Amy's parents, but to them as well, the lingering effects of human behavior's most callous capabilities trapping them like the silk of the various spider webs lurking on the fringe of Dwight's fateful journey.