Rolf, a sex-advice columnist and a lecher, has affairs with numerous women, but never a permanent relationship. Suzanne, one of his ex-lovers, offers to bet that no woman can get Rolf to propose marriage, a bet her girlfriend Andrea eagerly accepts. But there's a catch: To win the bet, Andrea must get the womanizing Rolf to commit to marriage without first going to bed with him.

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.

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.

In Ceylon, American Babs Lincoln, daughter of US Ambassador Jefferson Lincoln, is kidnapped. At the same time, an employee of the US Embassy in Colombo is murdered. The crimes bring Joe Louis Walker, alias Inspector X, and Tom Rowland onto the scene, who quickly realize that the cases are connected.