In Aix les Bains during the early 20th century, Celia Harland, a beautiful (of course) young English girl down on her luck is befriended by a rich widow, Madame Dauvray, an addict of "spiritualism", and stages seances for her benefactrix, while knowing full well that the supposed manifestations from the spirit world are entirely bogus. This set-up supplies the opportunity for a criminal gang master-minded by Madame Dauvray's maid, with their eyes on the widow's jewellery collection, to engineer an introduction for one of their number, Adele TacÔe ("Rossignol") whose taunts of disbelief goad the old lady into allowing a seance to be held which, unsuspected by either Celia or her patron, will be the cover for murder and robbery.