ArseneIt's the main character and code name of captain Louis de Reignier.
Definitions:
A personal name."Arsene is recognized as a new hero in the city."
LupinIt's the last name of the main character, Arsene Lupin, a kind of Robin Hood character.
Definitions:
A surname noticeably used in the book The Crystal Stopper."Lupin outsmarted the detective yet again."
CrystalIt's the main object that the story revolves around. The stopper made of crystal.
Definitions:
A piece of a homogeneous solid substance having a natural geometrically regular form with symmetrically arranged plane faces."The crystal stopper was the only clue left at the crime scene."
CaperA playful jumping movement or a high-spirited adventure, usually related to some sort of crime.
Definitions:
A playful jumping movement."He went off in a caper after stealing the jewels."
An illegal plot or enterprise."The whole caper had been carefully planned."
HeistIt's a planned robbery or theft.
Definitions:
An act of stealing; robbery."The bank heist was orchestrated by Lupin himself."
MastermindIt's a person who plans an undertaking or scheme.
Definitions:
The brilliant planner of a complicated scheme."Arsene Lupin was the mastermind behind all the thefts."