Matthew McConaughey teaches the finer points of hanging oneself.

Ellis and Neckbone are two Arkansas 14-year-olds living up a tributary of the Mississippi. Early one morning, they pilot their little motorboat to an empty island out on the big river, where they find a bigger, better motorboat stranded in a tree, washed up there by floods. But as soon as they decide they're going to fix it up and get it back on the water, a mysterious stranger appears. Mud (Matthew McConaughey) makes a deal with them—if they bring him some food, they can have the boat.

Of course, Mud's hiding out from the law, and while the echoes of Great Expectations are undeniable, writer/director Jeff Nichols (Take Shelter) finds a beautiful coming-of-age story in this Dickensian riff. What Nichols absolutely nails is that sense of boyhood receding into maturity, of Ellis and Neckbone's make-believe adventures suddenly turning into a very real one. Tye Sheridan and Jacob Lofland are both outstanding as Ellis and Neckbone, respectively—and McConaughey is generally okay, too, except for the one scene where he has to howl in emotional pain and literally pound sand.

The best parts of Mud all involve the two kids, but there are some terrific supporting performances, too: a steely Sam Shepard as the creepy old man who lives across the river and a hilarious Michael Shannon as Neckbone's philandering uncle. (There's also Reese Witherspoon as Mud's estranged girlfriend, but let's move on. She isn't awful, I guess.) Toward the end, Nichols allows his plot to run amok—there's a ridiculous shootout and an encounter with a pit of poisonous cottonmouths that seem particularly contrived—but these false notes pale in comparison to what Mud gets right. At its heart, it's a sad, sweet story about growing up and discovering that adults don't hold all the answers. If that sounds like a cliché, Mud offers a worthwhile variation that contains real feeling. recommended