The Crystal Stopper

Arsène Lupin faces an opponent who can turn his cleverest plans against him. In Maurice Leblanc's The Crystal Stopper, Deputy Daubrecq disrupts Lupin's robberies and leaves members of his circle under arrest, with the guillotine threatening them. Recovering control means saving his men as well as repairing a reputation built on audacity and disguise.

The contest revolves around information and concealment. Leblanc drew on the Panama scandals of the 1890s and adapted the idea of an object hidden in plain sight from Edgar Allan Poe's The Purloined Letter. Those influences place political corruption and a deceptively visible clue inside the machinery of a gentleman-thief adventure. The chapter sequence moves from arrests and a death sentence toward the object, the enemies surrounding it, and a final confrontation.

First serialized in Le Journal from September to November 1912, the story belongs to the early Arsène Lupin cycle. Daubrecq matters because he denies Lupin the effortless superiority that often drives a caper. Personal loyalty, public scandal, and the pressure of time narrow the thief's room to improvise, making deduction inseparable from rescue. The mystery asks whether mastery of appearances is still useful when an adversary understands the same game.