Phantom Thief Alexandrite

Paris, late 19th century. The mysterious thief Alexandrite appears as if to ridicule the decadence of the world.
From green to red, it bewitches Paris at the end of the century like a bewitchingly glowing variant of a jewel!
The prize is not a diamond ring or a masterpiece of a national treasure! We come to you to get your "most precious thing"...