An infamous arms dealer bequeaths his castle and a large collection of his patents to his beautiful young widow (Mireille Darc). These valuable patents would give its beholder an edge in the international arm race, so the Secret Services from several countries are sent to retrieve these priceless documents at any cost. The French agent Legneaux (Lino Ventura) in under orders to seduce the heiress and retrieve the documents it's Spy vs. Spy in this hilarious action-packed comedy as these super agents tryto outsmart each other and survive the other's deadly traps. The stellar cast includes Bernard Blier and Francis Blanche with great direction by Georges Lautner and writing by Michel Audiard. The writer, director and three leads had worked together the previous year in the very successful gangster comedy, Monsieur Gangster (Les Tontons Flingueurs).