Buster Garnier has been hired by a struggling automobile company to go around Paris, tossing flyers wherever he goes, flyers that look like 5,000-franc bills on one side and an ad on the other. When he returns to the main office to get more flyers, he mistakes a stack of real francs — five million francs, in fact — for the flyers he’s supposed to hand out, and takes them instead. Back on the streets of Paris, he begins throwing the money out to everyone he sees (including a very depressed-looking groom forced to marry an ugly girl), unaware that he is causing near riots wherever he goes. During his excursion, he meets a beautiful girl named Germaine, who desperately needs money to pay the rent. He falls immediately in love with her, and the money he gives her solves her financial dilemma. Alas, when he arrives back at his company’s headquarters, his now frantic employers fire him, so he is left looking for a job.
An unhappy Buster visits his mother, a prompter at the Théâtre du Parc, who gets him hired as a stagehand. Unfortunately, on his first night, he accidentally gets himself stuck into a knight’s helmet and demolishes an expensive stage set, ruining the show in the process. Now very depressed, Buster decides to commit suicide, but he’s equally unsuccessful at that. When he attempts to fill the kitchen with gas, the gasman shows up and turns off the flat’s gas because the bill hasn’t been paid. Then he goes to a nearby café, intending to drinking poison that he has mixed in a glass of water (but it tastes terrible, so he adds sugar). Just as he’s about to drink the poison, however, he is approached by a grateful Germaine, a waitress at the café, so he changed his mind and asks her for a date. Back at home, Buster’s mother shows up and gives him the good news: he has been cast in the theater’s new production. He will be playing the bit part of Prisoner No. 2 in the play Le Roi des Champs-Elysées.
On August 21, the day the play premieres, some gangsters meet outside the walls of a nearby prison, helping their chief, “Scarface Jim,” escape, but they get separated after the breakout. With the exception of a large scar, Scarface Jim is identical to Buster Garnier.
Meanwhile, during the opening night show, Buster stumbles his way through his performance, with Germaine the only one clapping for him. Between acts, they meet in the park, where Germaine tells Buster he was wonderful. After she leaves, Scarface Jim’s henchmen stumble upon Buster, mistaking him for their boss, and take him off to their expensive, trap-laden mansion. Meanwhile, the irate theater manager mistakes Scarface Jim for Buster, who knocks him cold and then heads off to the mansion. , trying to get “Buster” back into the theatre to finish his performance, gets punched out by Jim in the park. Jim then rushes off to get to the hideout. The theatre staff is now frantic, trying to find Buster for the final scene of the play.
At the mansion, a nervous Buster is toasted, saluted and “reintroduced” to “his” very amorous girlfriend. As Buster tries to find his way out of the situation, Scarface Jim arrives, causing confusion among the gangsters until he reveals himself via the skull-and-crossbones tattoo on his chest.
A chase through the house ensues as the gangsters, led by Scarface Jim, try to lay their hands on Buster, but Buster has discovered many of the house’s trapdoors and other secrets. He finally outsmarts one of the hoodlums into letting him out of the house, where he steals one of the gangsters’ cars, soon followed by gangsters shooting at him from another vehicle. Buster cleverly draws the attention of the local constabulary, and now they begin chasing after the gangster who are chasing Buster. He leads the gangsters and the police to the theater, where he runs on stage and instigates a fight between the police and the gangsters.
The audience members, who had been so bored they’d started falling asleep, are roused by the fighting and gunfire on stage. Assuming it’s all part of the plot, they begin cheering and applauding wildly as the police finally round up the gangsters and Scarface Jim, hauling them all off to jail.
After the performance and curtain calls, Buster — now a hero — is back at the park bench. Germaine arrives, and reaches out to embrace him. When she kisses him, Buster pulls her close, smiles and says, “Oh, baby!” as the film fades out. — Nick Ciccone