Audrey Hepburn plays the bookish Jo Stockton who is swept off her feet literally when the pushy editor of the foremost women's fashion magazine, Quality, Maggie Prescot (singer-composer-arranger Kay Thompson in her first major film role), and her photographer Dick Avery (Fred Astaire, (leading fashion photographer Richard Avedon was credited as “visual consultant) invade the Greenwich Village second-hand bookshop where she is working to do a fashion shoot. Avery sees great potential in her and although Jo is disdainful of the fashion industry when she finds out it means a trip to Paris where Professor Flostre (Michel Auclaire) teaches his philosophy of "empatheticalism" (a none too sly dig at Sartre and existentialism) she agrees to model for them.
So it’s off to Paris to indulge in a period-typical idea of Left Bank exoticism and even less convincingly the obligatory romance between the 28 year old Hepburn and the 57 year old Astaire (whose wife had recently died). Hepburn shows herself to be quite an adept singer and dancer whilst despite the years, Astaire is Astaire, even down the spats and straw boater, his best number being a solo piece in which he emulates a bullfighter beneath Hepburn’s window.