The Crystal Stopper is a thrilling crime novel that follows the adventures of the legendary thief, Arsene Lupin. When a crime is committed during a burglary at the home of Deputy Daubrecq, two of Lupin's accomplices are arrested. One is guilty, while the other is innocent, but both face the death penalty. Lupin, known for his cunning and daring, takes it upon himself to uncover the truth and save the innocent accomplice from an unjust fate. As he investigates, Lupin encounters a ruthless blackmailer who possesses an incriminating document hidden within a crystal stopper. This document holds the key to the truth, but Lupin must find a way to retrieve it before it falls into the wrong hands. With his signature wit and resourcefulness, Lupin unravels a web of deceit and danger to expose the true culprit and bring justice to the innocent.