In The Case of the Obliging Tourist, the Contessa di Malliori was the London end of a jewellery smuggling racket. Described as a dark, attractive-looking woman of middle age, the Contessa was an Sicilain who came to Britain during Mussolini's regime and soon became one of the city's best known hostesses--which raised the question for Biggles: how did she afford it?
The answer appeared to come from a smuggling racket which she ran with an accomplice and fellow Sicilian Carlo Antonio Barrosa. Barrosa took advantage of unsuspecting and innocent English tourists in Nice and asked them to carry small parcels to England to post on their return. The parcels went to an accommodation address offered by a tobacconist Otto Cermak. The Contessa then retrieved the parcels under a false name of "Mary Jones". In this way, valuable jewellery could be imported without the need to pay duty. The Contessa would then sell them through her network of society acquaintances. In some instances, the jewellery, besides being contraband, were also stolen goods.
The Contessa's scheme was exposed when an English tourist, Alice Hall met and told Biggles what had happened. With the help of Gaskin and Marcel Brissac, a sting operation was planned in both Nice and London. The Contessa was arrested by Gaskin when she turned up at Cermak's to collect yet another parcel despatched by Barrosa, who was also arrested at the Nice end.