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.
World War I aviator Carbot attempts to establish a commercial airline after the war, for the purpose of delivering the mail to the outermost regions of France.
The series follows the adventures of lighthearted Jean-Paul Moulin, a police Commissaire, and his team as they solve crimes.
