Arsène Lupin goes undercover, wearing disguises, to locate a well hidden crystal bottle stopper. He also has to figure out what makes that particular bottle stopper valuable.
The Château de Tornbull has gradually become a center of feverish tourist activity, which deeply upsets Stefan, the young Count of Tornbull, the landlord of the estate. All the more as among the visitors prowls around an uncanny individual, who seems to covet the precious paintings in which the Tornbull family takes so much pride...
