
Professor Charles Buisson, astronomer and Nobel Prize winner, has just discovered a nova. He informs the other observatories by telephone. Just as he thinks one of them is calling back, he finds himself on the line with a young woman threatening suicide at the Ruban Bleu cabaret, if her lover hasn't joined her by midnight. Intrigued, the professor decides to go and prevent the unfortunate woman from committing suicide. One of his students, who earns her living as an understudy in a knife act, helps him in his investigation, while the school principal and a policeman suspect him of being a prankster or even of selling drugs. For the scientist, it's an opportunity to discover a world of music-hall that he'd never known before: "I thought I knew the sky chart by heart, but there's one planet that was totally unknown to me: Earth. I'll be back!

Michel Simon
Professor Charles Buisson

Brigitte Auber
Gisèle, student of Buisson

Henri Génès
Lucien Mosca, boss of Ruban Bleu

Germaine Kerjean
Mrs. Rédéri
Anne Campion
The determined trafficker

Philippe Mareuil
Pierre-Dominique, aka 'Pépé'

Robert Lombard
Maurice, Buisson's assistant
Georges Galley
Patrice
Suzanne Norbert
Mrs. Buisson

Gaby Basset
Henriette, washroom attendant

Micheline Dax
The indecisive snob
Leila Lampi
Russian Princess
Janine Clairville
Woman from Paris

Nadine Tallier
Poupette, presenter of the show

Annick Tanguy
Woman from Paris
Liane Morice
Woman from Paris
Nikitine
Woman from Paris

Liliane Montevecchi
Woman from Paris
Jacqueline Ventura
Woman from Paris
Gisèle Fréry
Woman from Paris
Jean Boyer
Released