Paris 1920. Mr. Julien (Michel Galabru) has been a bellboy with "Maxim'S" for many years. Perspicacious, affable, helpful and stylish in his shimmering uniform, he is the indulgent accomplice of the great men of this world and the small women who gravitate around them. Also, when he announces to his boss his desire to abandon the profession, he refuses, threatening to reveal the true source of his income. Mr. Julien therefore continues to officiate, but reluctantly. Especially since he is brought to share his secret with his nephew Octave (Francis Perrin) and that his young mistress causes him concerns by falling in love with one of the revelers of the famous restaurant. The latter, the Marquis du Velin (Daniel Ceccaldi), a ruined nobleman, believes he can restore his coat of arms by marrying Julien's own daughter. She refuses and it is Octave who will marry him, Octave who takes the place of his uncle at "Maxim's", who can finally taste the joys of a happy retirement in his sumptuous property. But Octave does not have Julien's fingering.