Dan Casey enters a small western town where the brothers of a local girl, Beulah, are forcing Doc Henry Logan to marry her. When the justice of the peace asks if anyone protests, Dan claims that Doc is married to his sister, and a melee breaks out among the wedding guests, from which Dan and Doc escape by crawling under the fighters' legs. The two were partners in crime until Dan was jailed, and now they escape into the hills, where they greet each other joyously. Although Doc wants to go straight and open a saloon in Chicago, Dan insists that they pull one last cattle-rustling deal to finance the operation. When Doc balks at the idea of robbing a store for equipment, Dan cheers him up by offering to rob a bank in order to pay the shopkeeper. During the robbery, Doc almost foils the job by stopping to pet a dog, but Dan rescues him. Meanwhile, in the nearby town of Empty Cup, Colorado, Miss Amity Babb, who owns the town, raises the price of whiskey in her saloon in response to news that eastern liquor prices have increased. When her love-struck boyfriend, Sheriff Granville Dix, proposes, Amity states firmly that she cares only about money, and later chastises dancing girl Miss Dovey Barnes for degrading herself by falling in love with her customers. On the trail, Dan and Doc follow the mooing of cattle and, after a series of mishaps, manage to fashion a branding iron and wrestle a cow to the ground. After finally changing each of the animals' brands from Bar O to Cross Bar Q, they ride the herd into Empty Cup and attempt to sell it at the bank, which Amity owns. During negotiations, while Amity grows attracted to Dan, he realizes they have stolen Amity's own cows, and are now trying to sell them back to her. Their plan is stymied, however, by the news from Amity that feed prices have spiked in the East, making cattle too expensive to own and care for. As they are talking, the cattle, whose gate Doc failed to fasten completely, begin stampeding through town, causing chaos until Dan manages to round them up again. Discouraged, Dan and Doc decide to leave the cows in the pen and flee, but Dix gathers a posse and chases the pair down. Although Dan and Doc are ready to admit to rustling, Dix accuses them only of "cow abandoning," and forces them to return to Empty Cup. The next day, they try releasing the cattle on the range, but again are turned back by the posse, and discover that no one in the state can afford to buy their herd. Doc, hoping to return the herd to Amity, confesses to Dix that he stole the cows, but Dix assumes he is lying and laughs. Dan and Doc go to the saloon, where Doc drinks away what little money they have left. When Dan hears that bartender Henry Dick Coryell has a toothache, he announces that Doc, who earned his nickname by studying dentistry for six months, can cure him, for a small fee. After wrenching out Henry Dick's tooth with pliers, however, Doc loses the money at the roulette table, necessitating several more tooth extractions for the hapless bartender. That night, Dan hatches a plan to distract Amity while Doc robs her safe. Dan visits Amity and kisses her, and although she pulls a gun on him, she soon explains it is to force him to continue kissing her. By the morning, Dan and Doc have stacks of cash, but a suspicious Dix warns them that if he sees them with any money he will know that they are the safe robbers. Unable even to buy feed for the cattle without raising suspicion, Dan and Doc are forced to turn to Amity for a loan, but she archly reminds them that she has been robbed and cannot afford to give credit. In response, Dan plans to replace the money in her safe, and directs Doc to distract Amity. Although she seems to respond to Doc's efforts at seduction, Amity merely wants to give Dan enough time to return the money, and after kissing Doc, asks when Dan will be finished. Later, she agrees to loan them feed money, but at such a high interest rate that they soon owe her hundreds of dollars. Hoping to escape Empty Cup, they then hijack the railroad train, but crash it into the station house, causing a massive shootout throughout the town, and are arrested. Two weeks later, Amity informs the pair that she is willing to buy the cattle back, but after they sign the contract she reveals that the price for feed has dropped, making cattle valuable again. Although Dan is desperate to re-steal the herd, Doc insists that they give up crime and head to Chicago. Once again, however, the posse brings them back to town, where Amity announces that they owe her almost $4,000 in interest payments, which they can pay off by working as ranchhands. Dan, Doc, Dix and Amity begin to argue, and in the confusion Amity reveals that she is trying to trap Dan into staying in town and marrying her, prompting Dan to angrily insist that they be married immediately. Just then, Beulah, her brothers and the justice of the peace, who have been chasing Doc for weeks, arrive, and Amity declares that a group wedding will take place. As all the men pair off with the women, including Doc with Dovey, the justice of the peace asks if anyone has any objections, after which each man pulls out his gun, ensuring silence in response.
