Tye Sheridan and Jacob Lofland, Mud

Ellis and his friend Neckbone (Jacob Lofland) are two reasons "Mud" grabbed me immediately. They are boys who're most at home outdoors, on the river. Their world isn't one of home video, Xboxes and iPads but of dirt bikes (Neckbone built his own) and outboard motorboats. I don't run across boys like this in New York, or for that matter in Southern suburbia these days. But I knew them growing up, and I still encounter their like when I venture down to coastal North Carolina.

One day on an island in the Mississippi, Ellis and Neck (Sheridan and Lofland give note-perfect performances as the teen river rats) come upon a battered cabin cruiser that a flood has left surreally stranded in a tree. It is inhabited by the aptly named Mud (Matthew McConaughey, who's terrific), a gnarly local ne'er-do-well who's now in desperate straits. For the love of Juniper (Reese Witherspoon), the object of his (mostly unrequited) affections since childhood, he killed a Texas lout who beat her up, and now the cops are hunting for him and the Texan's family are aiming to ice him.

Ellis and Neck's decision to help Mud is what sets the plot's gears turning, and they turn expertly and inexorably. But much of what accounts for the film's particular poetry comes from things along the plot's edges, the textures of the human and physical world that Nichols conjures: the mercurial moods of the river in changing light; the lore these characters have imbibed from the land (Mud knows why the Cherokee puts snake skins on the bellies of pregnant women); the look of the rugged riverside buildings, battered mobile homes and low-rent strip malls that comprise their world.

In the narrative's depths, meanwhile, are hints of age-old regional mythologies. Ellis' ardent efforts to reunite Mud with Juniper (whose hands are tattooed with Shakespearean/Keatsian nightingales) may obviously deflect a desire to forestall the collapse of his parents' marriage, but more distantly it also echoes a traditional Southern adhesion to the codes of chivalry and courtly love: Even if the boy can't "save" the fair lady whose chevalier he sets out be, the endeavor initiates him into manhood.

Appropriately, the mythology associated with Ellis (whose name suggests Ulysses, another voyager seeking to reclaim his home) is trumped by one associated with Mud (whose name of course evokes Adam, primordial man), a myth that's always more powerful and profound in the South. For the arc of Mud's story is one of sin and redemption. He has killed (and who knows what else) and, though he imagines otherwise, he cannot achieve an easy salvation by grabbing Juniper and running.

On the contrary, he must undergo trials and opt decisively for self-sacrifice over safety (he twice risks his skin to save Ellis') in order to die (at least apparently) and then, after a kind of de facto baptism/cleansing, be resurrected. (Spoiler alert: Like the New Testament, the film has a happy ending.)

Flannery O'Connor would love this story, I think, as would Faulkner and Mark Twain. Yet Southerners, like other moviegoers, don't tend to massively embrace any film simply because of its high-lit resonances. That's why native Arkansan Nichols made an interesting wager in also embracing the propulsive genre mechanics of another big Southern author, John Grisham, as a way of broadening the film's appeal.

Applaud that wager or not, it has resulted in a very adroit piece of commercial storytelling that is also, in its cultural and emotional heart, quintessentially Southern.