Theatre performance Arsène Lupin - and the Queen's Necklace

There's a lot of excitement on the Simplon Nostalgia Express. The eccentric Sophie von Falkenstein receives a mysterious letter. It announces the theft of her extremely valuable necklace - the Queen's Necklace. The jewelry is to be stolen at midnight by none other than Arsène Lupin, the greatest gentleman crook in history. Only one person is in a position to prevent the theft: Inspector Ganimard, Lupin's greatest adversary. It is clear to him that anyone could be the thief, because Lupin is a master of disguise. A showdown between two brilliant minds ensues. Can Ganimard thwart the coup? Or is Lupin a few moves ahead of him after all?