Max Rutgers, a gullible good Samaritan, has been engaged to the ever patient, hard working Margie Solitaire for five years. Concerned about her daughter's future, Margie's mother, Mrs. Solitaire, criticizes Max's chronic inability to earn a living as an auto mechanic and his freeloading friends, Gus Harris and Harold "Rocky" Baker. Max believes that fame and fortune will be his as soon as Gus passes his horse trainer license exams, thus enabling the pair to buy a horse and race it to victory. The conniving Gus, however, has flunked every exam in the last five years because he forgets the answers when faced with a panel of questioners. Nevertheless, Max patiently tutors Gus at his auto repair shop, where taxi driver cum bookie Rocky takes bets. Rocky and Gus constantly quarrel, each charging that the other is taking advantage of Max. After Gus flunks his exam once again, he proposes that they capitalize on Max's unique ability to gulp down large objects by robbing a bank and then swallowing the holdup note. Fearing that Margie will lose patience with his empty promises of marriage, Max agrees. Dubbed "the paper eating robbers" after they collect $28,000 from the Mercantile Bank, Max and Gus decide to head East to buy a race horse. After Max insists that they pay back the bank with the horse's winnings, the pair buy a horse named "Tattooed Man" at auction and establish the Gus-Max Farms. Once the horse loses his first race, the animal-loving Max commiserates with the steed and offers to share his vitamins with him. Rocky, meanwhile, wonders how his friends could afford to buy a horse and decides to break into Max's auto repair shop, where he finds the empty bank pouch. The vitamins invigorate Tattooed Man, and when Rocky shows up and demands his cut from the robbery, Max and Gus tell him of the horse's remarkable performance, and they decide to bet their entire savings on the race. Tattooed Man easily wins, but later is disqualified on a foul. Broke, Max is forced to sell his car, and Gus and Rocky try to persuade him to rob another bank. Aware that Max is more concerned over the horse's feelings than his own financial insolvency, Gus convinces Max to rob a bank so that the horse can have another chance to be a winner. Together, Gus and Rocky plot a robbery using Margie's nondescript car for the getaway. After kidnapping Grace Havens, the elderly teller, Max orders her to open the vault, only to discover that an employee named Mr. Schroeder has the key and that the vault is on a time lock that will not open until morning. To distract the frail teller, Max takes her on a sight-seeing tour, causing the exasperated Rocky to resign from the robbery. Come morning, Schroeder arrives and Max tells him to open the vault. When the police come to cash their paychecks, Gus, waiting outside in the getaway car, drives off, leaving Max behind. Max fills a basket with money and has Schroeder carry it outside, where he discovers that Gus is gone and decides to hijack Schroeder's car. After driving off, Max drops Schroeder at a street corner, then parks the car and jumps on a bus with the cash. Back at the garage, Rocky comes to claim his cut of the robbery, and when Max offers him only $10,000, he threatens to sue. After a witness identifies the license plate number of the getaway car, the police tail Margie to her house and arrest Max and his gang. Some time later, Gus, Max and Rocky, now in prison, listen to a sports broadcast over the radio as Tattooed Man, who had been acquired by the bank in a "forced" sale, wins $50,000 in a race.
