Her father's murder sends teenage tomboy Mattie Ross on a mission of "justice" to avenge his death. She recruits tough old marshal "Rooster" Cogburn because he has "grit" and a reputation for getting the job done. They are joined by Texas Ranger La Boeuf, who is looking for the same man for another murder in Texas. Their odyssey takes them from Fort Smith, Arkansas to deep into Indian Territory (present-day Oklahoma) to find their man.