Garner plays a drifter who is gradually making his way to Australia, for no discernable reason. He arrives in an unruly western town that's been through three sheriffs in the past two months and is now in desperate need of another. The town council is not choosy, and he is hired almost sight unseen. Then he sees the jail - real nice, but no bars for the cells. He picks the most incompetent man in earshot (Jack Elam) for his deputy, and sets about cleaning up the town. Garner is adept at all the usual gun tricks and is in fact an expert marksman, but he prefers to talk his way out of tight situations, always getting the better of his intellectually-challenged opponents.
The real trouble begins when he arrests a whiny ruffian (Bruce Dern) for murder, and books him in one of the cells without bars. In the true western fashion, his crotchety pop (Walter Brennan) and all his brothers ride into town to engineer a jailbreak. What happens next would be criminal to reveal here, except to say that it consists of one comic gem after another.
Each line is written and delivered to perfection by a cast that seems to have been formed from a convention of old character actors. Brennan is hilarious sending up his Old Man Clanton role from "My Darling Clementine." His very presence in any western gives it a feel of authenticity, but here he proves to be a good sport in spoofing one of his definitive parts. Elam, Dern, and Harry Morgan contribute priceless support, and Joan Hackett is effective as Garner's most unorthodox love interest. All this would be for naught, however, without Garner in the central role. It calls for a very specific type of actor: quick-witted, sarcastic, astute, overly accommodating, and not especially tough. This is a tailor-made role for Garner, and he fills it in such a way that any other casting would be inconceivable. Thanks to him, the other performers, and the droll, clever screenplay, the film hits all the right notes for a pleasant and genial western comedy.