Although both coatroom attendant Louis Blore and songwriter and emcee Alec Howe are in love with Club Petite singer May Daly, she claims to be interested only in rich men, such as her devout admirer Willie. After Alec sings her a touching love song he has just written, however, May admits that she loves him, sending him into a joyous frenzy. Alec's happiness is shortlived as, moments later, May tells him that she is still marrying for money to avoid ending up like her poor, broken parents. Alec condemns May's stubborn pragmatism and storms out of her dressing room, aware that she is going out with Willie. To help his friend, fortune-teller Rami the Swami causes Cheezy, a waiter at the nightclub, to dump salad on Willie's head. May sends the drenched Willie home and leaves the club by herself, but is soon joined by the lovestruck Louis. On the way home, Louis fawns over May, but she is too confused about her romantic situation to be flattered by his attentions. Later, at the club, dimwitted telegraph messenger Charlie gives Louis a telegram informing him that he is the winner of the $150,000 Irish sweepstakes. Once over his initial shock, Louis goes on a spending spree and declares to a radio reporter that he is marrying "DuBarry," the character May portrays in her nightclub act. Louis' statement is also reported in the newspapers, and when May sees it, she is surprised and flustered. Alec, too, sees the announcement and challenges May to accept Louis' proposal. To spite Alec, May tells Louis, who has rented the club for the night in order to celebrate his windfall, that she will marry him, but makes sure he understands that she is only interested in his money. When Alec learns about May's engagement, he accuses Louis of being a fool, prompting May to slap him and run off. Charlie, who has taken over Louis' cloak room job, suggests that Louis slip Alec a "mickey" to disable him for a few days. Louis relucantly agrees, but accidentally drinks the drugged cocktail and collapses on the club floor. While he is unconscious, Louis dreams that he is seventeenth century French king Louis XV, and that May is his lover, Mme. Du Barry. Although he is aided in his pursuit of Mme. Du Barry by Charlie, who has been transformed into his son, the Dauphin, Louis soon discovers that she is attracted to The Black Arrow, Alec's dream persona, a rebel leader. The Black Arrow has condemned Mme. Du Barry for encouraging Louis to plunder the treasury in order to buy her extravagant gifts, but she is nonetheless smitten with him. The Black Arrow's rebel army is thwarted when the prime minister, the Duc de Rigor, who resembles Willie and has been jealously spying on Du Barry, orders the king's soldiers to intercept them near Louis' palace. Over protests from the duke, Louis insists that The Black Arrow be given a fair trial, then condemns his rival to death in court. As The Black Arrow is being led to the guillotine, Mme. Du Barry begs Louis to spare him, vowing never to see the rebel again if he does. Louis agrees, but before the execution can be stopped, the duke reveals that he is in love with Mme. Du Barry and engages Louis in a sword fight. A superior swordsman, the duke chases the king around the palace and is about to deliver the fatal stab when Louis wakes from his dream. Once recovered, Louis tells Alec that he deserves May more than he and offers them $10,000 as a wedding gift. After the reformed May turns down the money, declaring that she and Alec are "starting from scratch," Mr. Jones, the tax collector, demands that Louis hand over $80,000, and Louis is a poor man once again.