Captain Benoît manages to take possession of the plans of a new German airplane. The German counter-espionage assigns one of their agents, beautiful Erna Fiedler, to seduce Benoît and to eliminate him. But the two spies fall in love.

In 1917, in a small village in the North, Abbe Gaillard is suspected by the Germans of facilitating the escape of French and Belgian soldiers. A false alibi makes him innocent and he can thus continue his mission, thanks to the devotion of an Alsatian who, in enemy uniform, obscurely serves his country.

The mysterious death of a well-known criminal sparks an investigation into national security.

Michel Thierry is asked by the Second Bureau to go to Provence to help two colleagues, Leroy and Orcado, who are monitoring a gang of arms dealers. As soon as he arrives, Orcado is shot and leaves him an incomprehensible message in which three words are written: Sarah, Métis, Yerco...

The Secret Service abducts a "rocket scientist" to better protect him against gangsters acting for Chinese agents.

During a plane crash, Professor Sellier, an atomic scientist carrying very important documents, dies and his papers are stolen. Bordy, a sergeant in the Second Bureau, is asked to take Sellier's place in his family's home, in order to make the kidnappers believe that he is not dead.

A spy is instructed to investigate a case of arms and women trafficking covered behind a funeral services company.