This talkative and unevenly paced feature finds Fou (Jean Lefebvre) the inventor of a gas that makes the users fall in love. He is chased by his boss, the police, and spies, who seek to secure the secret recipe for their own selfish purposes. A shadowy American underworld figure tries to intimidate the inventor. A half-hearted attempt at comedy tries to go along with the double dealing and trickery of the thin plot of the film.
Jean Lefebvre
Eugène Ballanchon, scientific researcher, single
Maria Latour
Régine, Mr. Beauchard's spy
Bernard Blier
Mr. Beauchard, executive secretary linked to a gang
Michel Serrault
Mr. Granger, director of the scientific laboratory
Pierre Tornade
DST inspector
Pierre Brasseur
Father Ballanchon
Margo Lion
Mrs. Ballanchon, Eugène's mother
Robert Dalban
Merchant, spy in the laboratory
