Amos Tucker and Theodore Ogelvie, a pair of bumbling holdup men now going straight, arrive in the "boom town" of Junction City to start anew. But the duo end up causing havoc while getting cheated out of their money by two bank robbers named Wes Hardin and Hank Starrett. Things worsen when Amos and Theodore end up being suspected of the robbery and end up on the run from the town's feared lawman Marshal Wooly Bill Hitchcock, who developed a personal vendetta toward Amos and Theodore after they accidentally humiliated and injured the marshal on two occasions. To escape Hitchcock's vengeance, ditching their donkey Clarise, as she was used by the robbers, Amos and Theodore enlist in the United States Cavalry at Fort Concho. But the duo's bunglings and a run-in with a now insane marshal, who found them by following Clarise, result in the fort being burned to the ground. The following day, the fort commander Major Gaskill is relieved of his position while Amos and Theodore are placed in a military jail. But the "jail" turns out to be a cover for a robber baron named "Big Mac" who proceeds to recruit Amos and Theodore for an upcoming train robbery. Still determined to go straight, the boys attempt to extricate themselves from the situation by attempting to warn the local sheriff. The sheriff not available, they are told to visit the saloon as there is a visiting U.S. Marshall. After dressing up as bar-room dance girls to hide themselves from Big Mac's gang, having another encounter with Hitchcock and making a trade for blankets to hide themselves, Amos and Theodore accidentally end up on the train Big Mac is targeting before. Amos and Theodore, with the help of Jeff Reed, an army intelligence officer who posed as an enlisted soldier to uncover a conspiracy of military robberies, and Major Gaskil's daughter Millie, they arrest the robbers and their inside man Lt. Jim Ravencroft. Soon after given pardons, Amos and Theodore decide to resume working at Russell Donovan's farm.
of The New York Times thought that Kenneth Mars was "very funny" and that Harry Morgan "has some nice moments" as well. Variety wrote that the film "lurches from one set piece to another, in a fashion that makes its 88-minute running time seem much longer. Conway and Knotts have perfected their bumbling routines to a very minor art form, but principal laughs are supplied by drunk jokes, and character names such as Jack Elam's Big Mac. When hamburger trademarks become chief yock-suppliers, time has come to look elsewhere." Kevin Thomas of the Los Angeles Times called the film "delightful," with "much humor and action. Indeed, it's more inventive — and eventful — than the more sophisticated comedy-western '.'" Gary Arnold of The Washington Post dismissed it as "the latest uninspired attempt at juvenile comedy from the Disney studio."
