The Grand Vampire, under the alias of a real estate broker “Treps”, meets Juan-José Moréno (Fernand Herrmann), a businessman, who asks for an apartment with a safe. The Grand Vampire puts Moréno into an apartment whose safe is rigged to be opened from the rear through the party wall of an apartment belonging to Irma Vep and the Grand Vampire. However, the case Moréno places inside contains the Vampires’ black attire. Later, in disguise as bank secretary “Juliette Bertaux”, Irma learns that a man called Mr. Metadier has to bring ₣300,000 to another branch. In the event that he is unable to make the delivery, Irma will. Soon afterward, Mr. Metadier is murdered by the Vampires and his body thrown from a train. When Irma is about to take the money for him a spectre of Mr. Metadier appears and takes it instead. The Grand Vampire pursues the spectre, who escapes down a manhole. Later that day, Mme. Metadier appears at the bank, saying she hasn’t seen her husband in days. They also find out that the money hasn’t been delivered. Philippe learns of this and goes to the bank in disguise. Recognizing the secretary as Irma, he finds her address and a few hours later sneaks in, using Mazamette as a ploy. Irma and the Grand Vampire open the safe from their side, only to find Metadier’s body and the money. Philippe tries to capture them but is knocked down and they escape. Philippe calls the police just as Moréno enters and finds his safe opened from the other side. He walks through and is caught by Philippe. Moréno is revealed to be another criminal in disguise, and claims not to have killed Metadier, but to have found his body by the train tracks where the Vampires had dumped it. Moréno found Metadier’s letter of authority on his corpse, took Metadier’s body home, disguised himself as Metadier, put the body in his safe, assumed Metadier’s identity, took the money, and put it too in his safe. The upshot is that the money is now in the Vampires’ possession. The police arrive and arrest Moréno.