After seventeen years in prison, the former respected Parisian banker Paul Lavond flees with his friend, the lunatic scientist Marcel that is researching with his wife Malita the miniaturization of animals and human beings to improve the resources of mankind. Paul Lavond was framed for robbery by his scoundrel associates Emil Coulvet, Charles Matin and Victor Radin that had stolen his business while his family was doomed to shame, poverty and tragedy. When Marcel reduces the retarded servant Lachna, he learns that the woman is motionless and only responds to the control of his brain and has a heart attack. After the death of Marcel, Paul Lavond sees the chance to use the miniaturization process as instrument of vengeance and he travels to Paris with the insane Malita disguised of Madame Mandilip, a nice old lady and owner of a dolls store. Paul Lavond, using the identity of Madame Mandilip, befriends his resented and estranged daughter Lorraine Lavond and plots a scheme to revenge and vindicate his family name.

With a torrid past that haunts him, a movie theatre owner is hired to search for the only existing print of a film so notorious that its single screening caused the viewers to become homicidally insane.