Set in the Old West territory of New Mexico, "Appaloosa" revolves around a pair of hired guns (Viggo Mortensen and Ed Harris) who come to clean up a dangerous town run by a ruthless, powerful rancher (Jeremy Irons) and his band of outlaws. While boldly bringing new order to the town, the two fearless lawmen meet a provocative outsider (Renee Zellweger) whose unconventional ways threaten to destroy their decade-old bond.