In the 1870s, young Mattie Ross learns that her beloved father was gunned down by his former handyman. But even though this gutsy 14-year-old is seeking vengeance, she is smart enough to figure out she can't go alone after a desperado who's holed up in Indian territory. With some fast-talking, she convinces mean, one-eyed US Marshal "Rooster" Cogburn into going after the despicable outlaw with her.