A young inventor is kidnapped to force him to tell the secret of his invention, but he foils his captors thanks to a pen with invisible ink.
Director:
Renée Carl
Juliette Michaud
René Navarre
Le détective Julien Kieffer
Paul Manson
Emile Darbois
Jean Devalde
Jean Brémond
Fernand Herrmann
An Accomplice
