"The means used by foreign spy services to obtain the trade secret of a French invention."
Claude Rollet
as Yves Rubin
Danielle Godet
as Sonia
Paul Préboist
as Léon Prades
Jacques Galland
as Robert Alexandre
Henri Lambert
as Dabillaud
Daniel Prévost
as Mario
Michèle Chemin
as Janine
Christine Aurel
as Irène
Dennis Berry
as Jean-Marc
André Rouyer
as Pierre
Jean Rupert
as The man on the train
Jean Perrin
as The representative
Paul Pavel
as W (the spy)
René Couderc
Director
