In a small Arkansas town, Ellis (Tye Sheridan) and his friend Neckbone (Jacob Lofland) set out for a small island in the river, where Neck has discovered a boat stuck up in a tree. The boys are surprised to find a man living in the boat. He is Mud (Matthew McConaughey), and he says that he is there to try and rescue his true love, Juniper (Reese Witherspoon), from her family, who disapprove of their relationship.
And he asks for the boys' help. Ellis is at the age where girls are just starting to become interesting, and his views of love are still romantically idealized, so he's delighted to get involved. Needless to say, the course of true love is not going to run smooth, and once you throw in his parents relationship struggles and his own fumbling attempts to impress an older girl, Ellis is headed for some painful disillusionment.
The re-creation of Matthew McConaughey as an actor to be taken seriously continues here; he's learned to calibrate his drawl with remarkable precision, and he's got it cranked all the way up here. Mud knows exactly how to manipulate Ellis to get what he wants, and you can see the gears turning behind McConaughey's eyes as he schemes and connives.
As good as he is, though, it's Tye Sheridan who most impresses here. It's a beautifully subtle performance, and not an easy one. There's an intense confrontation late in the movie, in which Ellis calls Mud out on his deception and cruelty; it's a scene that could have gone horribly wrong in so many ways, and would have in the hands of most young actors. But Sheridan plays it impeccably, and the moment is heartbreaking.
Mud is not quite at the level of Nichols' previous film, Take Shelter, but it's a darned good movie.