A stranger enters into and forever alters the life of a couple. He claims to be pursued by certain authorities who intend to prevent him from disclosing a secret that only he holds, whence the title. Is he lying, or insane - or is he telling the truth? Who, if anyone, is after him? And what *is* - the secret?

• Président Films
• Valoria Films
• Jean-Louis Trintignant
• Marlène Jobert
• Philippe Noiret
• Solange Pradel
• Antoine Saint-John
• Michel Delahaye
• Maurice Vallier
• Frédéric Santaya