A nightclub entertainer temporarily replaces a tycoon he's famous for impersonating.

American entertainer Jack Martin and his French girl friend Colette are performing in the Cote d'Azure nightclub on the Riviera when the audience rushes out to watch a television broadcast of the landing of famed aviator Capitaine Henri Duran. Duran, who is also well known for his romantic escapades, is greeted by his lovely and patient wife Lilli, and his two partners, Philippe Labrix and Louis Forel. Jack is stunned by his uncanny resemblance to Duran, and soon after, when nightclub owner Capeaux threatens to fire him unless he comes up with a sensational new act, Jack decides to perform an impersonation of Duran. Lilli, Duran, Philippe and Louis attend the opening of Jack's new act, and Duran is entertained by Jack's portrayal of him as a world-renowned woman chaser. When he goes backstage to congratulate Jack, Duran meets Colette, and, charmed by her beauty, invites her to an upcoming reception at his house. Meanwhile, Jack goes to the bar, where he meets Lilli and Louis. Lilli is amused as Jack flirts with her, and after she leaves, Colette throws her purse at the infatuated Jack. Later, Philippe and Louis see Lilli chatting with Felix Periton, Duran's chief rival and the proposed buyer of fifty of his new planes. Periton, who is aware that Duran is having financial difficulties, is delaying signing the contract for the planes in order to force Duran into bankruptcy. Unaware of her husband's problems, Lilli invites Periton to the reception, which is to be held that evening. Louis and Philippe are horrified by the situation, especially when they discover that Duran has left for London to ask a friend for a loan. Desperate to hide Duran's absence from Periton, Louis and Philippe hire Jack to impersonate the aviator at the reception. Jack agrees, although he insists that Lilli not be told of the impersonation so that he will not develop stage fright. Without Jack's knowledge, Louis and Philippe do tell Lilli about the charade, and she is so amused that she plays along. Periton tries to involve Jack in a business talk, but Louis and Philippe rescue him by lying that he has received an urgent call from the Air Ministry. Meanwhile, Colette, furious that Jack is missing, decides to attend Duran's reception in order to make Jack jealous. Upon her arrival, however, Colette sees the nearsighted Jack's glasses in his tuxedo pocket and realizes that he is not Duran. Colette then reveals that Capeaux has arranged for their performance that evening to be broadcast on television, and Jack eagerly makes his excuses to Lilli and promises to return shortly. As Jack is leaving, however, Duran returns home and sees him. Duran deduces that Jack has been impersonating him at the reception and watches Jack's television performance with a nervous Louis and Philippe. Despite Colette's warning that she will end their relationship if he returns to Lilli, Jack rushes back to the Duran home. There, he is ambushed by Periton, who insists on learning the details of his conversation with the Air Ministry. Duran and his partners anxiously await the results of Periton and Jack's "negotiations," but Periton leaves without revealing the details. Duran, worried that Lilli is enamoured of Jack, does not tell her that he has switched places with his double. Unknown to Duran, Lilli was aware of his subterfuge, and the next morning, when Duran tells Louis and Philippe that he spent a romantic night with his wife when she thought he was Jack, Louis and Philippe assure Duran that Lilli was only trying to teach him a lesson. Their debate is interrupted by the arrival of Periton, who pays Duran thirty billion francs for his planes. Although he is thrilled by Jack's accidental business success, Duran concocts an elaborate lie to convince Lilli that she spent the night with Jack. Lilli is mortified by the thought that she inadvertantly betrayed her husband, but when Jack stops by the Duran home to retrieve his clothes, she learns the truth. Lilli asks Jack to make Duran jealous, but Jack instead tells Duran that he should end his womanizing and pay more attention to Lilli, who is devoted to him. Duran takes Jack's advice, and later, goes with Lilli to the nightclub to watch Jack perform. Duran has also persuaded Colette to reunite with Jack, and she blows a kiss to Jack as he sings.