Mud 

There’s nothing original about Mud, yet it casts a little spell on the audience. Maybe that’s because it has such old-fashioned pacing — leisurely and lyrical, like a well-crafted drama from the 1980s — or because it takes place mostly outdoors, in a world washed by sun-glimmers from the Mississippi River.

Writer-director Jeff Nichols (Shotgun Stories, Take Shelter), a specialist in southern atmosphere, seems to be aiming for modern-day Mark Twain with this coming-of-age tale, shot in his native Arkansas. His Tom Sawyer is Ellis (Tye Sheridan), a 14-year-old who lives on a houseboat and spends most of his free time working and playing in the timeless world of the river. Exploring an unfrequented island, Ellis and his friend Neckbone (Jacob Lofland) discover a boat bizarrely lodged in a tree, and then the guy it belongs to.

Mud (Matthew McConaughey), who’s lying low on the island, suggests both a never-quite-grown-up Huck Finn and a figure from folklore. Everything about him is a little larger than life, from the “lucky shirt” he refuses to take off (sorry, ladies) to his obscure origins to his tales of his One True Love, Juniper.

Young Ellis laps up the romance. His mom just announced she’s leaving his dad, he has a hopeless crush on an older girl, and he’s trying to find a path to manhood that won’t involve getting his heart broken. Mud has other problems. A wanted fugitive, he needs practical aid as desperately as Ellis needs fantasy.

When Ellis sees the real-life Juniper (Reese Witherspoon) looking haggard in the local supermarket, Mud’s tall tales begin to pale under the fluorescents. But the boy still hopes to engineer a reunion of the lovers that will vindicate his own ideals.

This is classic, if well-worn, material. With the wrong actors and a folksier style, it would have sunk into hokum, but Nichols keeps things stark and honest. His actors deliver nuance without fake notes, from the two kids to veterans such as Sam Shepard, Michael Shannon and Joe Don Baker in memorable supporting roles.

If the pairing of McConaughey and Witherspoon makes you expect at least one scene reminiscent of a romantic comedy, don’t. They both do strong, unglamorous work in Mud, and they do it separately, though her role is more like a sliver of one.

McConaughey doesn’t quite explode his sun-drenched man-child persona here, the way he did when he played a psycho in last year’s Killer Joe. But he does give it dark undercurrents of deceit and impulsiveness, making us wonder along with Ellis if Mud is a trickster, a simpleton or a bona fide white knight.

Nichols’ script never fully resolves that quandary, even when it takes us outside the boy’s limited perspective. Mud remains a figure who’s a tiny bit mythical; as his name suggests, he belongs to the landscape, sleeping rough and representing an older, more grounded way of life.

Like Beasts of the Southern Wild, Mud pledges unqualified, unironic allegiance to a place most Americans would see as a doomed backwater. It gets under our skin because Nichols gives us time to come to know Mud’s island like the places we knew as children and hence to share Ellis’ sense of loss when it turns out not to be an inviolable Neverland. Some viewers may find that approach tedious, others hypnotic. But it could leave you nostalgic for a place you’ve never been.