Lupin, posing as Bernard d'Andrezy, visits Gournay-Martin, the wealthy champagne owner. A reception is held, during which the guests tour the cellars. During the tour, Andrezy makes strange chalk marks on the walls. In the evening, a telegram upsets those present: “Arsène Lupin is among you”. The Prefect of Police takes an immediate interest in the case, and one of the guests accuses Andrezy of being Lupin, having noticed his strange behavior in the cellars. A manhunt begins, and Lupin ends up trapped in a cul-de-sac. His old enemy, Commissaire Guerchard, has the pleasure of handcuffing the notorious burglar for the first time.