After the discovery of two murders, Commissioner Chabrier, of the French secret services, is investigating the disappearance of plans affecting the national defense of the country robbed by a gang of international spies.
Slip and Sach are working for a local newspaper as a reporter and photographer, respectively. Slip wants to get the goods on a local gambling ring that is fixing sporting events, so he and Sach go undercover to expose the ring.
A hated country gentleman is murdered, and the inspector on the case takes the veiwer through his thoughts about the possible murderer and motives as he questions everyone concerned.