Born into a family of actors, Françoise Dorléac, Catherine Deneuve's older sister, began her career at the age of 15. She shone a few years later alongside Jean-Paul Belmondo in "L'Homme de Rio". From there, a great international career is announced to the young actress. But in 1967, a few months after filming the "Demoiselles de Rochefort" with her sister, she died tragically in a road accident, at the age of 25. Nevertheless, she leaves behind an abundant career and thus continues to be present in the minds of cinephiles.
Juliette Vidal is a journalist in Paris who works for the glamorous magazine "Pénélope". Uninspired, she decides to take an interest in the life of a department store saleswoman Juliette Rozenec.
Unos ingenieros pertenecientes a una organización militar están ensayando un nuevo tipo de rayos que desintegran en el aire a los aviones. Una organización extranjera se apodera del aparato cuya clave es rescatada por el Servicio Secreto francés. Bersen, jefe de la organización, trata por todos los medios de recuperar la clave para poder venderla a un agente secreto de otro país.
