The two friends Marie and Hannah spend a vacation together in Italy. While Hannah has just been divorced, the fun-loving Marie throws herself into an affair with the Viennese surgeon Xavier Gruber. However, he only wants a vacation flirtation without consequences - and leaves her the business card of car mechanic Xavier Martin, which he received by chance, when he leaves unexpectedly. Back in Germany, Marie begins to write ardent love letters to the supposed doctor in Vienna. The shy mechanic is initially amused, but eventually falls in love with the letter writer and confesses his feelings to her without clearing up the misunderstanding.