It’s official: Jeff Nichols, who gave us the brilliant Take Shelter, is a writer/director who stands among the best of them. Matthew McConaughey plays the title character, a chipped-tooth, wild-haired drifter living in a boat in a tree along the Mississippi. Two kids, Ellis and Neckbone (Tye Sheridan of The Tree of Life, and Jacob Lofland) stumble upon him, and find themselves part of his strange and dangerous world. McConaughey is just catching wave after wave lately, and this is his best one yet. He makes Mud a little scary, yet charming and cunning. Sheridan and Lofland are terrific as the young friends who should probably stay away from guys living in boats in trees. The cast also boasts Reese Witherspoon, Michael Shannon and Sam Shepard, all of them equally great. Ladies and gentleman, we have the year’s first “excellent” movie. Jesus, it took long enough.