I certainly have a problem with René Clair .I've been watching his movies for years and forgetting all about them.I should love him,as I love Duvivier,Renoir,Carné,Gance,Grémillon ,Pagnol and all the celebrated directors of that great era but I can't .Even when he introduces French can can I can't.
Like some of his colleagues ,notably the highly superior Julien Duvivier ("la Charette Fantôme" "flesh and fantasy"),he had a penchant for the fantasy genre."Paris qui dort" and this movie were the first attempts in that direction.It continued with "the ghost goes west" "I married a witch" and "'this happened tomorrow". No wonder he made his best American film with a "rational" whodunit ,Agatha Christie's "And then there were none" aka "ten little Indians" .
His screenplay is old hat ,straight out of the ark.Just compare with Renoir's "La Petite Fille Aux allumettes"(or Epstein 's "Chute de La Maison Usher") for the silent era and Maurice Tourneur's sensational "La Main Du Diable" or Lherbier's "La Nuit Fantastique" for the talkies .And I will not even mention Carné's "les Visiteurs du Soir" or Cocteau's "La Belle et la Bete".Those artists created an eerie world and their movies are still strong today. Clair's movies introduce heroes who cannot stand the real world anymore,so they choose they will be ghosts and all course everybody will work out fine after some de rigueur episodes .It's light optimistic stuff devoid of any sense of drama .That could be valid comedy if Clair showed a sense of humor!But he is not Sacha Guitry,by a long shot! His plot is a trite melodrama : a father is forced to marry his daughter to a greybeard who is also a blackmailer ;and naturally the daughter is in love with a younger -but not particularly handsome- man.Thanks to a scientist ,the poor lover becomes a ghost who haunts the Moulin Rouge (check the title).And pretty soon the professor is charged with murder.That could have been a good plot,but it's neither really funny nor suspenseful.