The Good Guys and the Bad Guys (DVD, 1969) Robert Mitchum

Waco orders McKay to shoot Flagg, and when McKay refuses Waco abandons both of them. Flagg then takes McKay back to town only to find out that he has been "retired," and when he sees how clueless and incompetent the new marshal and the city fathers are, he persuades McKay that it is up to the two of them to stop Waco and his gang from ravaging the town.