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.
René Dary
Pierre Lusanne
Suzanne Dehelly
Colonelle
Raymond Bussières
Albert 'La Puce' Jacquin
Pierre-Louis
Charolles
Robert Berri
Jacques Mauval
Robert Le Fort
Basile
Emilio Carrer
Gambarra
Robert Blome
Jef Dooksen
René Robert
Luc Andrieux
Charles Brugeat
Roger Bontemps
Reporter
Marian
Jean-Jacques Lécot
Claude Larry
Bob d'Arcy
Jean Debray
Cooper
Jean Nosserot
Fuseau
Émile Genevois
Robert
Coussolle
Orgaert