Madama Brillante hosts the Dutchman Sumers and Italian bon vivant Don Polidoro in her London hostelry. While one flaunts himself as a important international dynamic businessman, the other longs for Italy, where you can laugh, be loud and above all eat well and cheaply. For some time now Livia, a daughter from a good Italian family, has set up home with Madama Brillante. She was abandoned by Milord Arespingh two years ago and has been looking for him ever since, as »Mademoiselle Enrichetta from Marseille«, word of whose beauty has reached Sumers and Don Polidoro. Livia and desperate to marry Madama Brillante quickly became close friends. Arespingh suddenly turns up at the hostelry. The aristocratic scion, in desperation, tells Don Polidoro that he had to leave his beloved behind in Genoa: his father sent him to Jamaica before ordering him back to London to marry an English noblewoman. The wedding's already been announced in the papers. Livia is shocked when she encounters Arespingh. Torn between happiness, longing, pain, mistrust and fury she’s determined to conceal her identity and take revenge. Arespingh tries, in vain, to explain and win her back. He intends to use his contacts to prove his innocence. In the meantime Madama Brillante tells Don Polidoro, who’s dying to meet the mysterious »Mademoiselle Enrichetta from Marseille«, about the magic qualities of heliotropes: the mysterious stranger uses one to vanish, but anyone who had one could disappear too, whenever they wanted … Don Polidoro must get his hands on a heliotrope! Part Two The situation escalates – with Don Polidoro, over the moon because he thinks he’s found a heliotrope, at it’s centre. He wants to marry invisible Enrichetta, a phenomenon Madama Brillante's instilled in his mind. Livia has increasing doubts about Arespingh’s guilt but can't quite bring herself to trust the desperate man. Sumers offers Livia his protection when he sees them having an argument. Then Madame Brillante announces that Livia’s going to be arrested, on orders from on high. Sumers generously uses his fortune to help Livia, but forbids her to leave his house. Madama Brillante, who’s still stringing him along about heliotropes, and Don Polidoro become closer. Milord Arespingh managed to change his father’s mind and avoid marrying Milady Lindane. Livia, whose arrest warrant's been recinded, can’t resist her love for him any longer and the couple, and imminent bride and groom, are reunited at last. Amidst the joy over this happy outcome, Madama Brillante confesses to Don Polidoro that she was pulling his leg about heliotropes. Another couple have found happiness – a wedding’s not out of the question here either.