During the Tour de France, five riders are found murdered with a red tulip near their bodies. A journalist and a police inspector lead the investigation to unmask the murderer.
as Pierre Lusanne
as Colonelle
as Albert Jacquin dit « La Puce »
as Charolles
as Jacques Mauval
as Basile
as Gambarra
as Jef Dooksen
as Charles Brugeat
as Le journaliste
as Tonnelier
as Fuseau
as Robert
as Annette Jacquin
as L'inspecteur en chef Honoré Ricul
as Le mécanicien (uncredited)
as (uncredited)
as Un inspecteur de police (uncredited)
as Le directeur de la police judiciaire (uncredited)
as Max Everkampf (uncredited)
as Le caissier (uncredited)
as Le maître d'hôtel (uncredited)