Jack France and the Singapore Pearl

Jack France has arrived in Monza for the 1928 Grand Prix. Meanwhile, at Gallery Ravelli they are waiting to display the famous Singapore Pearl - believed to be the most expensive pearl in the world. For the lucky few an invitation to this event is waiting. After reading a newspaper article Etta Clutterbuck believes things aren't quite what they seem and soon convinces Jack of the same. Is the pearl merely a diversion and if it is, what do the thieves really have in mind?