Bumbler Rusty Morgan and his fiancé Edith Enders set up a joint bank account that consists mainly of her life savings, and commiserate that Rusty's history of bad investments have left them too poor to marry. Rusty returns to work at a café, where his boss Avery complains about his constant tardiness. Con man Harvey Baker immediately identifies Rusty as an easy target, and starts a scam in which he pretends to be a rich man who discovers his uranium stock certificates are useless and so gives them away to Rusty. Baker's cohorts, Frankie Frannis and Rita DeLacey, then enter the café and convince Rusty that the stock is worth $10,000. When Baker then returns, Rusty admits he has learned that the stock is valuable, and Baker "generously" allows him to spend he and Edith's savings to buy it. The scam continues as Baker brings Rusty to a bank, where Frankie pretends to be bank president Harper and vouches that the stock is good. Later, however, bunko squad Lt. Ross Qualen visits Rusty at the café and explains that the stock is fake, and there is a $10,000 reward out for the swindlers. Avery overhears and fires Rusty, who offers to take Qualen to Harper, but when they reach the bank they are told that no Harper exists, and Qualen leaves in a huff. Edith is distressed to hear that Rusty has been fired, and grows more upset over the next few days, as he loses job after job for incompetence. One day, Rusty recognizes Rita's photograph on the outside of a dance hall, and follows her back to Baker's office. There, he pretends to be a salesman to get into the office, and then, once recognized, lies that he is a government agent. Pushing a pencil into Baker's back, Rusty claims it is a gun and nearly has the gang out the door when Rita knocks him out. When he revives, Baker convinces him that they are actually Federal Bureau of Investigation agents infiltrating the racketeers, and, promising to return Rusty's money, "hire" him as a secret agent. They send him off to collect monies from other marks, and one calls the police with Rusty's description. Without realizing it, Rusty evades Qualen and the police and deposits the money he has collected into a safe-deposit box. He returns to the office, where the gang, who know the police are on to them, "promote" Rusty to head of their company and sneak out the back door. The police enter, but Rusty, sure that his bosses are superior to the local law enforcement, refuses to talk and is arrested. After he is receives a five-year sentence, the crooks, certain that no one could be so gullible, assume that Rusty has stolen their money and is using prison as a place to hide while he launders the cash. While they plan a jailbreak to get Rusty back into their custody, Edith visits him and forces him to confess the whole story. When he steadfastly refuses to reveal Baker's name, Edith informs Qualen and the district attorney, who agrees to allow Rusty to escape and then have him followed. dAlthough the warden does all he can to let Rusty break out, the law-abiding prisoner barely notices, and must be helped out the door by the entire prison staff. Even then, he hops on a truck that drives back into the prison, and the police have to hijack the truck and drive it to Edith's house. Once Rusty calls Baker, however, the con man persuades him to elude the detective tailing him. Rusty meets the gang, who bring in a fake lawyer, drunkard Dipso Dave Rutherford, to acquire power of attorney from Rusty so the gang can access the safe-deposit box. Rusty recognizes Dipso Dave as one of the con men shown to him by the police, and finally realizes that the gang are not FBI agents. They force him at gunpoint to sign away his rights, but he signs the name Peter Rabbit and runs out, followed by Baker and Frannis. Rusty sneaks back into the office and calls Qualen, who convinces him to stay in the office until the police arrive. Rusty dons a series of costumes to confuse the gang, who chase him through the building but are easily distracted by his shenanigans. At one point, they capture him and drag him to the office, but there Dipso Dave knocks out Baker and Frannis. The police enter in time to arrest the gang. With his $10,000 reward, Rusty is finally able to marry Edith the next day.