In the short story The Last Seance, Raoul Daubreuil is the fiance of a famous Parisien medium Simone. To Simone's devote maid Elise, who objects to her seances, Raoul promises that after marriage, Simone would stop all her supernatural activity. He tells Elise that Simone has a wonderful gift , but that the life of a medium involves a terrible nervous strain and she has done her part.
However, it turns out that he is also the one who has been persuading Simone to continue with her seances for some time despite her wanting to stop. He has been her "managing agent". His motives are only partly about the money from satisfied clients. He is proud of Simone's abilities. Clients and scientists seem to be convinced that Simone is genuine and there is no trickery. Raoul shows Simone letters from renowned scientists who have requested that Simone sit for them occasionally so that they can study the phenomena that she brings about. He tries to persuade her to agree but she refuses. Raoul believes that for Simone to carry on, in the handling of the unknown, there must always be danger but her cause is a noble one because it is in the cause of science. Like the scientists, he also very much wants to study and understand Simone's supernatural phenomena.
Raoul prevails on Simone to conduct one last seance for Madame Exe. What happens next forms the main plot of the story.
Raoul is an engineer by profession. He is described as "a good-looking young Frenchman of about thirty-two, with a fresh-coloured face and a little black moustache."